I am using gutsy 7.1 after a failed attempt with hardy 8.04 upgrade
(luckily on a cloned copy of my gutsy system) on an athlon 1000 system
with 768 mb ram, 440 mmx ,3com lan, sb128 sound and all is ok.
I had driver problems with hardy, and the compatibility isse of
firefox 3 that hardy installs, and java 6.
I am not an expert as i am only 8 months down the line with linux.
As far as i can see if you run gparted from the live ubuntu cd or the
gparted/clonezilla cd it will do anything you like with partitions,
but if i remember right if they are flagged as locked you have to
unlock them first. As long as your bootloader knows where your system
partition is and you have a swap partition as well as your system one
it should be ok.
It is confusing that Gparted sees partitions as sda1, sda2, etc but
the bootloader would see them as hd (0,0) hd (0,1).
I will look into your problem and come back to you if i find anymore
info.