Depending how old your Hard Drive is, it may be going bad and causing some hang
ups. Or the IDE or power cable to the hard drive may not be in all the way? You
may have bad ram or too little ram, the processor may be bad, and so on. It
could be many of things. So the clue is that it hangs up on XP and Ubuntu, so
starting to debug hardware may be the key.
When does the system freeze up? Is there a program that uses huge amounts of
ram. Like a java application like Frostwire.

I have been having freeze ups with Feisty as well...just built my machine
about a month ago. AMD Athlon 64 4000+ CPU, 128 MB DDR Video Card, 1 GB of
DDR (split between 2 chips that say they work better than regular ram
somehow). I loaded Windows XP on one hard drive...no hang ups, but then
again no sound or anything like that...just the only way to play
Gunbound...anyways... I started getting freeze ups with Feisty Fawn. Edgy
Eft did not freeze up on me one time that I can recall (I upgraded to Fawn
through the update thingy). I have had a few suspected programs so far,
though not always is it when one or all of them are running (so that kinda
makes them not real suspects, right?). Everytime I freeze so far I have
either had Firefox, gAIM, or both running as far as I can recall. If either
of you figure out what is plaguing his system, it may help mine and vice
versa.

Ubuntu works perfectly for me. I run all sorts of applications that you can
imagine of. I have a telescope and use KStars to stargaze and parallely run
ktechlab for some digital circuit simulation and with so many browser
windows opened at the same time. I have had no problems what so ever. I have
even tried to load both cores to over 80% and use over 80% of memory and
swap, and it has worked for me. no freezeups.

Not just a Linux problem- Firefox stalls on vista too. Just plain quits.
have to switch to Microslof to get going a gain.

This is just my own experience but, every time Im called in to see why
linux is doing bad, I find its the quality of the computer or a duel
boot situation. But, if it doenst work - get Windows XP Pro. Never
failed me.

I'm surprised to see someone suggesting Win XP in an Ubuntu
forum. Don't get me wrong, I don't object to it. Since you mentioned
it though I've got a question. Do you know of any way to keep free of
spyware and viruses, etc etc, like you can in Linux and OS X. I'm
really interested since I still use Win XP for gaming and I teach
others how to use it.

Well, that was only in reference to someone moving away from Ubuntu. I
have advocated to my local school system, government and city council to
move to Ubuntu. But for those who cant or wont move to linux, win xp pro
is what I keep them them. Mainly because I spent so much time securing
my own systems that I can lock one down pretty well.

This is what I just did for a sheriffs department: Took 35 machines and
upgraded from NT4 to XP Pro and 5 on Ubuntu. I turn off all the services
that you dont need on XP. Disabled IE and Outlook. Turn off Auto
updates. I use three pieces of security software. I used to use
ZoneAlarm but I have found Comodo and its nice. I use Ad-ware from
Lavasoft and AGV. For the police I use the paid versions to get extra
features. I use a old pc as a firewall for the whole network. The Ubuntu
machines I just set up and run. Nothing much I have to do to them. I do
use firestarter on those but these are so freakin secure - for the
average users.

I hear of lots of people having bad things happen to their computer but
I have been lucky to never have that happen to me. I keep my spyware
and viruses definitions up to date and I keep watch on my system.
Staying away from IE is a important issue as well. Since I have taken
over the computers at a local school where they let kids play online
games after school hours, they have not had a single problem with their
computers. Im not a genius when it comes to computers - I just stick to
the basics, keep it simple, and use my head on what software is bad for
the system and then lock it all down.

But back to your original point, Ubuntu is very user friendly for the
most part and I always push that out first. My parents cant use it as
easy as Windows just for the fact that, if there is a problem its just
about impossible for me to talk them through fixing it. With windows,
everything is point and click.

Yes use a good virus protector.

I use Titanium from Pandasoftware.com but Nod 32 is also a top product.

Panda has a full system including firewall and it is unobtrusive in
operation.

Please put in mind there is bugs in the O/S as well with any O/S of any style.
One is to look into Ubies bug report web site.
https://launchpad.net/ubuntu/+bugs It may take some time to search through the
bug report. It not like Google. Yet, it is a good start to help solve on some
queer problems.
There is some solutions and some times it even have the geeks scratching their
heads. Please all so remember that Ubuntu is %100 free. It is not like you pay
some $200 for a O/S that has bugs here and there. Of course spending time on
getting the system to behave takes away from some personal time.
If some is running a 64 bit linux or windows kernel. They both have more bugs
than the 32 bit kernel. The good news that Linux is making more head way on 64
bit than windows.
So lets move forward... Woo weee!!!
OK Dr.Ice you say your system freezes on when GAIM and Firefox is running. What
kind of system lock up are you getting? Are the programs just stop responding or
the whole desktop stops. Like where you even tried to move your mouse or type on
the keyboard. Did you try ALT+F2 or CTRL+C and get no response? Does the system
seem fine after you hard reboot the system. A hard reboot is where you have to
hit the reset button or turn off and on the PC. When you have GAIM and FF going?
Is FF at a web site that has flash player? Do you have your web cam on when on
GAIM?
There is so many what if's and their can be a big IF. Your system has plenty of
power to run. So it could be what version kernel you are using to the ram is
being allocated to a different process.

I am running Edgy on a 64bit system with 4GB ram. Even with such
high ram capacity when reading and plotting grids on Matlab the memory
goes to the max. What I can suggest you do is to place the applet System
Monitor on your panel and see how the memory varies as you run
several applications. It may very well be that you are occupying something
that is choking your machine. When I accidentally choked mine a couple
of days ago, it went completely frozen and after a while it automatically
killed Matlab and memory went minimal. I suspect that Matlab (being mostly
developed for Windows) has a bug that doesn't know how to clear its memory.
Other than that my system is working perfectly.

Otherwise, check that all your hardware is compatible with each other. Failure
to comply would be responsible for such behaviour.