30D Error 99

So I used to get the odd error 99 starting about 8 months ago, like maybe once a month, now it's worsened to I get an error 99 after EVERY PICTURE. About 10% of the time the iris sticks shut until I reset it by removing the batteries.

Things I've tried;
Canon lenses, Sigma lenses (all of which work flawlessly on my XT)
Cleaning the lens contacts.
With and without the battery grip on.
Cleaning the battery grip's electrical contacts.
Most every mode on the camera.
SanDisk and Lexar memory cards. Formatted.

Are there any other ideas out there that I've missed to give a try?

I need something working for this weekend for the RedBull Air races in Windsor, plus this is extremely annoying happening on a regular basis.

Note: It does save the image taken, but instead of the image coming up, I get the Err99 screen, then either off and on, or pulling the batteries is necessary to get back in business.

Thanks.

sounds like the shutter has gone,and nothing other than sending it off will repair it.
my 40d was the same,dead.

good luck

But, the shutter works fine?

All the images come out perfectly. I thought when the shutter died you got those black banded images, or the shutter just plain stuck?

i must have read the post wrong! sorry

I think it's the shutter too... Might not be completely dead just yet, but very close and it sticks once it opens up... Just my guess! Replaced shutter in my 20D before, pain in the b$#@. Good luck!

It's the iris that seems to randomly stick at the aperture being used, but that doesn't happen very often, and it returns to normal after resetting the camera.