Hi Lisa,
What version of RobotStudio are you using, 3.1 or 3.2 ?
I am asking because we had a bug in RS 3.1 that caused the problem you describe. This bug is corrected in RS 3.2. If you are running RS 3.2 e-mail me your station and a backup of the VirtualController, so will I take a look at it and see if I can find the problem.
E-mail: anders.spaak@se.abb.com