Fairly common under Vista? are u on Vista..
Try this
1/ Locate the applications icon or short cut and Right click on it.
2/ From the Drop Down Menu select the Run As Administrator option.
3/ Now click the application icon or short cut and it should run.
4/ When the User Account Control (UAC) message appears enter the appropriate credentials if you are logged on as a standard user, and click the Submit button.
5/ If you are the Administrator and UAC is not configured to always require credentials, just Click the Continue button and the application should start.