Microsoft OCS 2007 R2 users were having communications issues with AOL's AIM when federating using PIC (Public IM Connectivity) and using a Windows Server 2008 (x64) Edge role server - Windows Server 2003 (x64) is unaffected by this problem. Microsoft's Scott Oseychik just issued a fix that solves the problem. The fix involves changing the Windows Server 2008 Edge role to initially establish the SSL dialog using the TLS_RSA_WITH_RC4_128_MD5 cipher suite.

It's pretty easy to fix via Group Policy (gpedit.msc). Once you make the fix you should be able to successfully communicate with AOL AIM clients using Office Communicator 2007 R2 via PIC.

Click here for the resolution.