Skype problem


Just installed skype on my new IMac G5 single 1.8 GHz machine.

Eveything works fine but I cannot get the microphone to work?

I have checked the settings in system preferances and mute is disabled,volume is turned right up.

I only have two input options, one of them being digital but with either selected it still dosnt work.

I am using a standard Genius microphone and I am getting no joy,I have run through the trouble shooting on skypes website but no joy.

Is there a silly setting that I need to adjust? is it a Tiger thing? do I need a Mac specific microphone?

Any advice would be great, im sure its more of a setting issue as I also have a dual processor MAc at home that does the same thing, I have also tried an alternative microphone with the same results.
Maybe not particulary helpful, but I have been informed that the Mac uses a non-standard microphone jack. I have had all sorts of grief trying to use headsets on the Mac, but got around it by getting a USB headset. Never had a problem since.
I use a a usb VoIP handset and often have to just reset the audio in apple - system prefs - audio, otherwise everything comes out of the on board speakers and uses the on board mike (I use a PowerBook G4). I think everything gets reset when I use i-Tunes.
I am not sure what kind of microphone you are using. I know that G5's do NOT have a microphone port. It is a Line IN port. That means whatever you plug-in it has to be separately powered for the device to work. This is done this way for clear,crisp professional audio in for music professionals. So if you still want to use that microphone, you will need a device that can handle it like Giffin's iMic.
Thats interesting..

Are there any techies out there that could confirm the Mac uses a non standard microphone Jack???