We're actively debugging this, and I'll update this post once we have this resolved. UPDATE (6pm, Eastern): We have identified the issue, and will be making changes this evening to rectify the issue. Things should be resolved by tomorrow morning. ...

Issue: Microsoft Office Communicator 2007 R2 in conjunction with Office Communications Server 2007 R2 would intermittently fail to communicate with AOL AIM clients via PIC. Note that this would only reproduce if your OCS 2007 R2 Edge role is running...