Sigma and the Canon ERR 01

[Sky Blue Iris]

Last night, about 30 minutes before I was set to leave to shoot the Harvest Moon, I was checking my Sigma 55-200mm f/4-5.6 DC as I rarely use it. I dialed it down to about f/22 and used the depth of field preview to click the iris in and out a few times. Well with the last click the iris stuck in the shut position and made an unfavorable grunt. Now I can't change the aperture and the auto-focus is messed up (it zooms, grinds and never focuses correctly) and after each shot the camera gives me the ERR 01 "your contacts are dirty, etc" error.

Has anyone had/heard of this problem before? The web doesn't have much info on how to fix it but a number of people have had their Sigma lens react badly with their Canons. I think I can send the lens back under warranty but I was wondering if there's a trick to resetting the lens electronically somehow.

Any help or advice would be greatly appreciated.