Computer Experts: Please help me this issue with prl_disp_service.

I have a MacBook Pro running OS 10.6.8; 2.4 GHz processor, 4 GB RAM. Every once in a while, prl_disp_service runs up the processor, taking around 98% of the CPU. I need to figure out why it’s using so much processing power and if there are programs I need to delete to prevent this from happening in the past. I did do some Google searching, but I’m still not sure what to do.

I ran this command (sudo launchctl list | grep -v ‘apple\|mdworker’PID) from the terminal as suggested on a forum I read, but I don’t know how to interpret the output or what to do next. I do have parallels installed, but I’ve never run it. I think restarting usually fixes the problem for a while, but I’d like to have it not come up again.

On a possibly related note, every so often (about once a week on average) the computer won’t let me open any applications. Anything I try to run just bounces in the dock but never opens. When this happens, restarting from the apple menu or using the power button doesn’t work. I either have to restart by holding the power button for a few seconds or using a sudo reboot command from terminal. If anyone can help me troubleshoot either of these issues, I would really appreciate it.