I bought the Nokia C7 a few days back, and it hanged more than 10 times on the first day!

I did a google search, and it turns out that hundreds of other people are experiencing the same problems:

1. Phone hangs then restarts after a few seconds

2. Unable to download and/or use apps from the Nokia OVI Store

3. Worst one - phone hangs, shuts down, then cannot be started up again for a while, like 30 minutes to a few hours

These problems occur VERY frequently.

Apparently Nokia rushed the launching of these phones to compete with Android based phones before complete testing has been done, so the software is still in its early stages. No sign of when the new software version will be released.

You can check out this forum to see some of the complaints and Tim Allen, Product Manager of the C7 itself posts about the phone:

http://www.allaboutsymbian.com/forum/showthread.php?t=96993
P/S: The C7 is REALLY nice to use, touch screen is responsive, interface is smooth and beautiful, so if you really want one, I suggest you wait until the problems are fixed.