The Yahoo option only allows Connections with full Functions from iChat TO iChat
Certainly Video and Audio cahts are iChat to iChat Only. (No PC or other Non iChat Buddies)
As far as File Transfers go, I have no info at present.
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb( 10.6.8)
Mac OS X (10.6.8),
"Limit the Logs to the Bits above Binary Images." No, Seriously