Issues with the network interface

[Les]

Hi everyone,
	On to my next great problem... I have given up on the low end graphics,
and will just get a new system (someday).
	However I have a different problem.  Networking seems to drop out a
lot, on both linux systems.  Windows, including windows XP on the dual
boot box seems to run fine.
	TCP dump doesn't seem to reflect anything bad happening, but apps
running in linux, including evolution, firefox, and Croquet, seem to
lose sync very frequently resulting in hangs, poor browsing (where I
must continually be hitting refresh to get the full window data), and in
Evolution, loss of sync during mail downloads any time there are 30 or
more messages (frequently with this mailing list stuff). This also seems
to affect downloads, occasionally hanging up during updates and other
real nuisance issues.  

	However I don't see any error messages in the system log.  Is there
somewhere to look to see what kinds of errors firefox or evolution might
be having with the network?

	I don't see anything related to networking in the system log, nor can I
find a log for firefox or evolution.  Any pointers from the experienced
among you to assist me in finding and fixing the problem?

Regards,
Les H