We saw this happen in earlier versions of TC when we had too many other apps running on the test machine and also if we had been running TC all day without restarting it. The objects would be read slowly and we would get something similar to your WindowsForm message and not what we expected.
We suspected there was a memory leak in TC but we were never able to duplicate it consistently in order to report it as a bug. The workarounds we found were these:
1) make sure only TC and the application under test are running
or
2) exit TC and the application under test and restart them both
or
3) exit everything and reboot the test machine
