How much RAM does your machine have?
What type of processor is in your machine?
What file format (jpeg/PNG/gif) are you using?

> How much RAM does your machine have?

1G

> What type of processor is in your machine?

athlon 64 bit dual core

> What file format (jpeg/PNG/gif) are you using?

various.



Thing is, on this identical hardware, XP is dramatically faster.

You are running far better hardware than I am. The only thing that I
can think of is that there must be a conflict with one of the file
formats that you are using. I've stored nearly every photo that I've
ever taken on my computers and I have not seen any difference in speed
between Windows' Image Viewer, Gnome's Image Viewer or the gThumb Image
Viewer/editing tool.

"conflict"?

Jpeg mostly, some GIF, some BMP.

What happens, if, for example, you open your abominably slow window, then
open a terminal window and enter "top".

Also, do you use kde or gnome?

I might live long enough to try.
Once I open the directory that's at the top of my pictures tree, the
system is almost hung. On gibbon, the window will grey out, then come
back, then go grey again, for a LONG time. I've never been patient
enough to find out IF it clears up, but I have waited more than 30
mins.

Ok, got that going..
Top shows nautilus running 10-80% of cpu, and pretty consistently 70-80% of mem.
I have 2G installed, not 1G, I'd forgotten.

Load average running about 1.3ish, 1.62, 1.73.
I have 2G of swap, and that's pegged now too.

I'm guessing it's trying to read in all the images to (something) and
not releasing the data?

Yep, Nautilus is trying to make thumbnails of all your shots, that is
why it is so terribly slow.

You could try the following (this works for me)

Go to places and open your home folder then goto edit -- preferences

you should now have the file managment preferences window goto the tab
marked preview.

You should see other previewable files, turn show thumbnails to never
and see if that fixes the problem.