Question : The following error occured attempting to save properties for group administrators

I am having great difficulty with a particular pc.  It will not let me add users to local groups (administrators, power users, etc.).  I have tried connecting directly to it via computer management console and have tried adding the user in safe mode w/networking, but still no luck.  Another issue I'm having is with a program called Autodesk Inventor 11.  When trying to open the program it first gives me an error along the lines of "Inventor could not register due to a program (Explorer) running.  Would you like to end the offending program?"  It doesn't matter if I select yes or no; I always get an error along the lines of "You do not have sufficient permissions..." even though I am logged in as a domain admin.

A little background on this PC:
- The hard drive was cloned from a master disk image.
- The SID has been changed to a unique SID
- This is a brand new computer (1 of 13 others that run fine)
- Running XP Pro SP3, dual core processor

Any suggestions?

Answer : The following error occured attempting to save properties for group administrators

Did you use sysprep before cloning, or some post-cloning tool to change the SID?

Sounds like some permissions are set very badly somewhere in the NTFS file system.

Also, does Autodesk inventor have some licensing tied to the specific disk image?  A lot of licensed and keyed software becomes unhappy when the SID changes.  Sounds like it works OK on the otehr clones, though?