I got an er99 on my XTi while trying to take pictures today. So I did the following to try to remedy it:
* Removed batteries from grip. Reinserted batteries.
* Tried 2 other lenses.
* Removed grip. Inserted a fresh battery into now non-gripped camera.
* Cleaned lens contact area on camera and on lens gently with a pencil eraser.
* Tried 2 other memory cards.
* Reformatted a memory card in camera.
* Let camera sit with switch on "on" without a battery. Reinserted battery.
Nothing worked. I still get the er99 message on my camera. Is there anything else I should try before I contact Canon? (And of course the warranty ended earlier this month.)

