I have the same problem. I contacted htc about this and they told me to send it in for repair.

 

Is this with the OTA update?

I had that exact problem with a slightly tweaked ROM, had to update the radio to get it working.

 

I had this issue, it was weird, I tried all sorts, took off all my apps, reformatted the sd card and put the phone back to factory reset, that managed to get it working, then re-installed all apps and everything back onto the phone and card, and it stopped working, but then for some reason it has started to work again.
Sorry its not really a helpful post but, there is hope!

 

My camera is starting, I can switch to 720p and even record but after I stop the recording it hangs and only shows a black screen. The only thing I can do is to press the home screen to exit. After that I need to reboot, otherwise my phone gets really hot and the battery goes down FAST (I did not tried to kill the process so I don't know if that could do the trick). Anyone else had this problem?

 

I've encountered the same problem, everything else has been working fine, when i go to video recorder it opens properly but when i want to record nothing happens or screen goes black until i press home button, then the phone gets hot and starts to drain alot of battery (CPU on 100%?). Tried force close the camera but it's still draining the battery so only solution so far for me is restart the phone. (My phone came with Froyo 2.2 stock)

Any ideas what could be the problem? Should i send it in for repair?

 

Delete the last clip you recorded! When I first used the camera after the upgrade to froyo the resulting video file was corrupted. After that everything worked fine.

 

Thanks! Solved the problem for me