Lotus Notes Copy/Paste Problem

We recently purchased a Dell Lattitude D610 for one of the partners in our office.  We use Lotus Notes release 6.5.4 for our e-mail program.  This specific computer is experiencing problems copying and pasting in Lotus Notes.  If he opens an e-mail that he would like to copy and right clicks on the section he wants copied and tries to paste in a new e-mail or in Word it will not copy.  Now if you use keyboard commands Ctrl C and Ctrl V to copy and paste it will work.  At first thought maybe some type of virus or spyware.  Ran virus check and found nothing.  Cleared away all spyware with Ad-Aware SE.  Second thought was that maybe there was a problem with wireless keyboard and mouse.  Uninstalled all software and drivers for them and installed brand new Dell USB keyboard and mouse, still same problem.  Next tried bringing the system up in Safe Mode.  It will work properly like this.  Copied Task Manager to see what was running.  Brought system up normally and ended all processes except the same ones that were running in safe mode and still same problem.  Have tried uninstalling and reinstalling Lotus Notes, no help.  Tried loading the user id on a different machine and it works fine so it's not an id problem.  We have 3 of these machines now and this is the only one experiencing this problem.  Running out of things to try!!!  Has anyone seen anything like this or know of anything else to try?  Any help would be appreciated.

Thanks!