Mark, I am both relieved and sad that someone else has the same issue. FWIW, I sent an email to Canon support this morning about the issue:
Camera locked up on me (completely unresponsive, no error code, shutter "clicked" as it happened), and I'm not sure how to proceed. I was shooting a hula show, had taken about 700 photos in a 10 to 15 minute window, when the shutter "clicked" and the camera stopped working. The red "writing" light was on, though I'm sure the buffer wasn't full as I was shooting in short bursts (maximum rate was set to 6 frames a second) and *not* holding the shutter release down. Also, when the camera is buffering, it's still responsive (menus work, etc). In this case, it was completely locked and unresponsive. I waited for 10 seconds for the writing light to go away. But it didn't. I then turned the unit off and on. Everything seemed to work, and none of the images were missing or corrupt. I've since run chkdsk on the memory card (Lexar 32 GB 1000X), and there were no issues found. I'm writing to you because I'm not sure how to proceed. I'm not sure if this is some incompatibility between the camera and the card, or an indication of something wrong with the camera given how it just cut out and became unresponsive.
The memory card is a Lexar 32 GB 1000x (I only use one card in the camera, this one, in slot 1). It's worked flawlessly for me in the past (I've taken a couple thousand photos with it). I've since run chkdsk on it to see if it had any bad "sectors," it did not. Since the incident, I've tested filling up the camera's buffer (using the same card both empty and with the photos from the hula shoot), and it worked as expected: new photos were still taken, but at a reduced rate as images were cleared from the buffer.
Has anything changed:
No. I had successfully used this combination in the past, having taken around 2,000 photos without issue. This was, however, the first time the camera had been on and in use for more then fifteen minutes straight. Not necessarily taking photos the whole time, but never off.
No error code. Just completely locked up with the red "writing" light on. None of the buttons did anything, and I couldn't get the menu to come up on the back of the unit. I waited for 10 secs or so for the red light to go away (again, I'm nearly 100% the buffer wasn't full), and it never did. I finally turned the camera off and back on. It came up without issue and worked fine. It's the lack of error code coupled with the "click" the shutter made as it just cut off, becoming completely unresponsive, that has me worried there might be something wrong with the camera.
I'll post here what I hear back.