In my experience, this a a pure client-side bogosity. To verify: try blowing away all the 'nsform*' and 'formpost*' files in your "C:\windows\temp" directory; if the problem clears up, make an effigy of Mark Andreesen, abuse it creatively, and call me in the morning. :)
*grinz* Well, this appears to have helped a bit. I don't seem to end up CSS-spinning on management screens but I don't think that's related. It appears I can submit forms too (yay!) but its still painfully slow (much slower than it was when I first installed Netscape) COuld that be because I'm working offline and some weird DNS lookup thing is happening or is it still a manifestation of the same problem? Out of interest, what is the problem that is solved by deleting the above files? cheers, Chris