Rara,
Do you have cable, DSL, or dialup?
I have AOL DSL and I experienced a similar problem when I upgraded to Win XP. To make a long story short, I ended up having AOL send me a different DSL modem because the drivers for the one I had were admittedly not compatible with XP (took them 2 months to admit it to me). But it would do exactly as you describe...just disconnect for no reason (would say network cable unplugged or something), and for me to reconnect online I'd have to reboot my computer... Was a real pain in the a**!!
