Parallels Desktop v5 will not open: "not responding"

Had been using Parallels 5 with XP previously;no problem. Now when Parallels opens first window appears and then it hangs; "not responding" and requires force quit.

Uninstalled and reinstalled: problem persisted. Removed all Parallels files with iTrash; reinstalled: problem persisted

Permissions OK; repaired directory with DiskWarrior; reinstalled operating system; cleared caches: problem persists.

Running OSX 10.6.5 on an iMac with 8 Gb memory. I presume there is a rogue file somewhere... but where?

Can anyone help?

Thanks.

RNB