Terminal Server and Errors in MES

We have an issue sometimes on our shop floor using MES on terminal server. If an error occurs and a box pops up sometimes it does not pop up in front of the current screen, or the user clicks outside the box and it falls to the background. Since they cannot see the items in the tray they assume that there computer has locked up and go to manual paperwork.

I have instructed them to hit "ALT- TAB" but they usually forget.

Anyone having this same issue & has found a solution?