Interesting that "big and bloated" Firefox 7.01 runs just fine on my antique Celeron 400 laptop with 256 mb. About 110 meg free after starting FF.
Have you tried to maintain it?
I had to fix my mother’s machine. We ended up having to wipe the HD just to get rid of her corrupted FF install. The thing was hopelessly broken.
Ditched FF, runs just fine. FF used to be decent, but now it’s bloatware.