Hi,
iChat's use of using SSL to connect to the AIM servers is relatively new.
I also think that AIM's own use of providing the ability to login via SSL is also not that old.
It seems that there are less SSL servers and that you are Dropped more frequently from the SSL servers.
In iChat this does need a manual reset (it will not Automatically reconnect).
Sometimes it can be sorted as quickly as going to iChat > Preferences > Accounts and un-ticking the "Enable this Account" box and then ticking it again, which will log it in again.
If it persists it does seem to be a better idea to turn Off SSL.
7:17 PM Thursday; May 17, 2012
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
iMac 2.5Ghz 5i 2011 (Lion 10.7.4)
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.7.4),
"Limit the Logs to the Bits above Binary Images." No, Seriously