Canon20D- Error 00? shutter is locked

So this is really worrying me. The other day i went shooting outside and all of a sudden my shutter button locks up and I can't focus on anything anymore. I think the error code is 00 (that number is shown where the aperture value is ). After 5 minutes of panicking, the camera worked again. Mind you, I have no idea how it got going again. The following day or so, I was taking some pictures at home and it did the same thing. This time I just turned it off hoping that the camera would magically work again the next day. However, it still isn't working. Does anyone know what may be the problem?

I shoot in Av mode, have a Tammy 17-50 on it that I just got, tried switching from my Ultra II Scandisk to another one but nothing. help plsss!

nm, followed the err 99 directions and now it works again......hopefully i won't have to re-activate this thread again...............

It happened with my 20 when I was using wide open aperture a couple of time. Turn it off, drop the battery out into your hand, put the battery back in and turn it on. If possible bump the aperture a little smaller or otherwise make an incremental adjustment and you should be fine. It's a well known glitch for the 20D.