Early shutdown - 10D??

[mpoole]

I'm having a problem with my 10d and was wondering if anyone has experienced a similar problem:
I put in a fully charged battery and within 10 minutes the camera shows a low battery warning. It then operates for a while (50 shots) and then shuts off the camera. If I put the battery back in the charger it shows 3/4 or even full.
Maybe a faulty voltage regulator??
It does this with two different batteries.
I'd like some input before I send it off to Canon Canada, because in my past dealings I've received comments like" It's supposed to work that way

Thanks
Mike

[CyberDyneSystems]

Hw old are the batteries themselves.. ?
Are they a name brand or generic?

It seems unlikely that two of them would die simulteanously,. I agree,. but as they age,. they can get to a point where they will "charge" but the overall out put volatage has dropped to a point where the Camera can't live off of the output provided by the now too far out of spec battery.

[mpoole]

The batteries are original Canon, one is almost two years old and the other is about one year old. Maybe it's time to give Sterling Tek a call...