If you have gdb installed on your machine, type 'gdb /usr/bin/nero' in a terminal. You should come to a command prompt. Just type in 'run' and Nero Linux should start. As you have the release package, you might hit enter sometimes to acknoledge the fact that no debug symbols are found.

After that, try to reproduce the high CPU problem. Once you have this issue, go back to the initial terminal, and hit Ctrl-C. You will then get once again the command prompt. What would be then good to have is a backtrace of all threads:

(gdb) info threads -> gives you the list of all threads. Each of them has a number, so for each number:
- type 'thread XXX' (XXX is the number) and 'backtrace'.
- paste the output here