Consider the following scenario:
You sign in to Microsoft Office Communicator 2007 R2 on a computer that has a version of Internet Explorer later than Internet Explorer 7 installed.
You start an instance message (IM) conversion with another user.
You try to send a file to the user.
In this scenario, only Cancel (Alt+Q) displays. You cannot see the file name and icon in the IM conversation until the file transfer is completed or canceled.
This issue occurs because a flag of the ActiveX control of Office Communicator 2007 R2 is not set. Therefore, Internet Explorer resets the size of the file transfer progress bar.
To resolve this issue, install the following cumulative update:
2647093 Description of the cumulative update package for Communicator 2007 R2: January 2012