open iFix pop-up from scheduler

Hi, I have a vb script in a scheduler that runs while an expression is true & opens an iFix picture (pop-up). In some instances even when the expression is true the pop-up does not show up. The scheduler is running in the background.
Any idea what might be preventing the popup? I understand the scheduler cannot open pictures when workspace is in configure mode but I have checked to see that the workspace is always in run mode.