Microphone problem!

[PaulMate]

Hi, for some reason my microphone isn't working. No it's not muted, yes everything I can find has been enabled, yes it's in the right socket. I just can't find out what's up. Here is an image that might give you a clue, notice how the "playback" icon is coloured but the "record" icon is greyed out. Why? What causes this? http://fitterhappier.org/pauls/ok.gif

 

[PaulMate]

Thx muchly appreciated!!