The Internal Microphone on my Eee 1005HAB does not work in 10.10. In 10.04 it didn't work very well (lot of static), but now it dosn't work at all.This is weird because it seemed to work fine when I used a liveCD of 10.10. I can plug in an external mic (usb or mic jack) and those both work fine. I think the internal mic is stereo.
Try this: (because the microphone isn't stereo but mono)
Use Pulse Audio Volume Control (typing
pavucontrol in the terminal) to unlock stereo sliders for the mic in 'Input Devices' tab. Drag the right slider down to zero.
I never had microphone issues in my EeePc. Have checked in your Sound Preferences if you mic isn't muted, with very low volume or even not selected? You could also try something like eee-control