This is going to sound odd but I have seen the same thing happen on my notebook. For some reason, my machine some times thiinks it has a second monitor attached to the left of my primary display. Other times, an app just opens 'off screen'. I run windows 7.
If I hover over the app on the start bar (in my case at the bottom or my screen), a second window or button will pop up. I right click on that, choose move, click and drag my mouse a little and then use the arrow keys. If going right for a little while doesn't work, try left then up, then down. It is possible the form is open off the screen. I can't explain why it happens, just give it a try.
If this doesn't work, try two martini's in quick fashion then try again. I find enough martini's makes anything less irritating!
Cheers!