Anyone shed any light on likely battery life for this cam ? I'm using 2 x 1000mAh AAA batteries and didn't get anywhere near enough footage today to fill a 4gb card before the batteries gave up on me.

Approx 2.5hrs with 1100mAh is the standard quote from GoPro.

Hmm defo got a problem with mine. It does me 2 hours sat on my desk but 15 minutes or so on the bike, obviously with some vibration.

The audio crackles when on a bumpy service so I suspect something is loose 🙁

Try turning down the bit rate when riding? If you've got it cranked right up it will use more power trying to smooth the picture.