Every time I restart my Mac (2X2.8 GHz Quad-Core Intel Xeon, 10.5.6) I get the message "Unable to connect to Parallels Service. Make sure that prl_disp_service is running or check your firewall settings." and Parallels shuts down. I have to uninstall and reinstall the Parallels Desktop each time I restart, then all is fine. Any idea why and what I can do to fix this issue? Thanks for any help.