Windows 7 Calculator crashes WPF Multi-Touch?

I have a rather strange problem with the CMI and WPF HMI that I am currently working on. HMI is a rather complex program that allows you to use to add and remove modules from the workspace, drag and drop and resize so that the page on which they operate is customizable. It works well and after optimization actually runs smoothly and works great with touchscreen and animations. One of the gestures in particular is quite useful, as you can (using multi-touch) place two fingers on the screen and swipe left or right to change pages.

However, lately I've been getting complaints from our app department that touch will randomly stop working for any kind of complex movement, read as any kind of multi-touch. I spent a few hours trying to figure out what the problem was and it turned out, oddly enough, to be associated with the Calculator window. Whenever the calculator is opened and then closed, the multitouch stops functioning and any breakpoints placed in the code show only one click. I took to the internet and found several articles confirming this problem, but nothing even hints at a fix, other than that the calculator does not work, which unfortunately is not an option since this HMI is for engineers producing precision parts and they are a bit tied to a calculator.

I shared the problem with its base in which I made a simple C # and WPF touch application that kept track of how much it touched, just to make sure it wasn't just crappy HMI programming. After getting the same results, no matter what I tried, I came here hoping that someone else would run into and maybe fix this issue.

Here are some specifications:

• This HMI runs on Windows 7 and is fully updated.
• It is a C # program using the Unity, Prism and WPF containers.
• Touch is handled through simple OnPreviewTouchDown and TouchDown Events
• It doesn't matter if I launch the calculator via Process in C #, or if we launch it from the actual OS, and how we close the program, all permutations have the same effect on every computer in the building with a touch on the screen.
• This is an ELO touchscreen with the latest drivers, although I have also tried it with the Vista Multitouch simulator and get the same results

Any help or direction would be much appreciated. Thank!