Connectivity Issues???

I notice while Im on the computer that AIM and Limewire are constantly breaking connections. It signs off but then signs right back on constantly and same with Limewire disconnecting and reconnecting but I have no disruption of actual internet service. I cant figure out why its constantly doin this. Thought it was my home network but it does the same thing while at school with a dedicated line.

Comp Stats:
HP Paviion ZV5000
Windows XP w/ Service Pack 1
Pentium 4 3.0ghz
384 Ram

any ideas???