Incoming calls, caller can't hear anything

[rowan.bradley]

I'm using the free version of Express Talk for Windows. It all worked fine for a while, but now something has gone wrong. If someone calls me, and I click the green phone icon (or press F10 which I have set up to answer incoming calls) it appears to connect, and I can hear the calling party, but he can't hear me at all. Needless to say, he assumes that I'm not there and soon rings off. If I make outgoing calls, everything is fine and both ends can hear, so my basic setup must be working OK.

 

What's likely to be the cause and the cure for this?

 

Thanks - Rowan