You are a Remote Call Control enabled Microsoft Office Communicator 2007 R2 user. You make a call or accept a call by using Office Communicator 2007 R2. This behavior causes the window focus to switch to the conversation window. However, you may not be aware that the window focus has changed. In this situation, the following issues may occur:
Dual Tone Multiple Frequency (DTMF) tones may be sent through the call if you are typing.
The call is disconnected if you press Esc and then press Enter accidentally.
Install the following cumulative update:
2291453 Description of the cumulative update package for Communicator 2007 R2: November 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.