It was recently brought to our attention that the popular open source IM client Pidgin — and potentially Adium in the Mac — are having trouble connecting to AIM and AOL messaging clients receiving a “Received unexpected response from http://api.oscar.aol.com/aim/startOSCARSession” error. There is a simple fix that has been confirmed to work from one of our staff members:
1. On the top menu click on Accounts
2. Modify your AIM or ICQ account
3. On the Advanced tab, untick the ‘Use clientLogin/Use SSL’ checkbox
4. Save and you’re done
The source of the problem is still unknown, however this fix seems to be working for everyone. BTW, going back and forth with previous versions of Pidgin will not work, so just try the above.