i've been having the same issue on my Motorola Atrix (android 2.3.6). the most recent update specifically mentioned something about helping with stability with camera crashing. it seems to do it even more now. for me a reboot fixes the issue. sometimes i can get away with just doing a "force close". to get this to work i have to first start the camcorder, wait for it to fail which takes about 20 or so seconds. then go Settings > Applications > Manage Applications > Camera and select force close. i haven't actually tried the "clear data" option here because i was worried it might delete the pictures. i'm guessing it doesn't, but rather be safe than sorry.
i would love to know what is causing this because it can exceptionally annoying when you need your camera quickly.