Sema4 drop down lists slow?

We had a customer who had a new installation of Sema4 (accounting and timesheets package) installed on a new pc and the performance of the software was abysmal in some cases. It was reported to me that if they opened the package and selected timesheets and then selected the employee drop down list, there would be a long wait for the dropdown box to appear and the program would appear to hang. I timed it and it took 7 minutes (for about 50 users) for the dropdown box to appear after it was clicked when the timesheet screen was first loaded.
The very strange solution is posted in the extended entry….

Several calls to technical support to try and troubleshoot the issue and we were not getting very far. However I noticed this afternoon that if I went into timesheets, clicked the dropdown menu and then went into another window, then went back into timesheets the dropdown box was populated immediately.
I then discovered that it didn’t matter what the first window was that popped up, the drop down boxes would “hang” until another window was opened and then the first window reacted correctly.
I called the support line, gave them my account number and the tech seemed to have an understanding about my problem and told me to change my windows theme to classic instead of Windows XP as this was likely the culprit AND to click in the empty space in the Sema4 window – when I did so, everything worked as normal. I was pretty confused as to why the theme was the culprit so after I was off the phone with support I set the theme back and reloaded Sema4. Loading the initial window and then clicking in the empty space of the mdi application and then clicking on the dropdown box, everything worked as expected.
This is the weirdest bug I’ve ever seen – just in case anyone else is having the same problem I’ve included a dummy screenshot outlining the areas of the application.

MDI mockup.MDI mockup. Hosted on Zooomr