Suddenly today we were alerted to a problem where our application "seems to hang" during an operation. We figured out what is happening: namely a response window is being "displayed", however it is not visible. When the user presses <escape> the invisible response window closes and the application is responsive again.
This problem only seems to occur on Windows Vista, and we have reproduced it ourselves. It happens in versions of our PB Classic application built using PB 12.5.2 (5006), AND PB 10.
Interestingly other response windows in our application display fine. The notable aspect of the problem response window is that it is somewhat larger.
Also interestingly we witnessed the EXACT same problem a few years ago when our application was published using Windows Terminal Services. Time passed and this problem under Windows Terminal Services went away. Citrix terminal services has never been a problem.
We are sure the response window is invisible rather than submerged under another window because we can "move" it by <alt>+<space> to get the window menu, then click "Move" and use the arrow keys.
At this point we can only speculate that a Windows Update has caused this. We are talking about an installed program behaving fine today, and not tomorrow. Nothing changed, and as mentioned above, we have reproduced it.
Feedback or suggestions are welcome!