Date format in Regional Settings

[jdodson]

I am having a problem with changing the date format on one certain user's machine from m/d/yy to anything else. It gives me an error stating something about "invalid characters, try again" but when you log him on as a local user he can change it. I let him log on to the domain on to my machine and he can change it there. I am lost at this point. Can you tell me other troubleshooting methods to try for this issue?