Profile problems and local copies

I know this is an age-old problem, one that has caused me many hassles over the years, and there's probably a billion threads on it already, but...

OK. Clients running Windows XP, IE 8. Students have mandatory profiles, more or less problem-free. Staff have roaming profiles which periodically go wrong; the most common glitch being that clients lose their Internet settings. I once tried staff on simple, fixed mandatory profiles, but this had problems of its own and I'd prefer not to. Clearing out all the useless random local copies of profiles on the PC people are having problems with usually fixes things temporarily. Staff routinely log into several computers simultaneously, which I suspect doesn't help. It seems to be the same handful of staff members that have 90% of the problems. Does any of this sound familiar? Any recommendations? :(