blinking battery icon for Digital Rebel XT - w/full charge

I just bought a digital rebel XT. This morning, I noticed the battery icon was blinking on the LCD, it was the only element on the lcd. So I thought,fine, it must be out of juice.

I recharged it.

I took 2 shots on a fully charged battery, and then the battery icon was blinking again. There were no bars inside the battery either. The camera would not let me take any pictures, it seemed locked up. I couldn't do anything.

I turned the camera off, then back on. Same thing.

I took that battery out, then put it back in. That worked, and now it seems to be working.

Anybody got any ideas what's wrong?

Thanks

Just to add, I am also using a Transcend 256 45X card, if that matters.

thanks for any ideas.