It could be now that my answer from a previous post could apply.
MIGHT THINK YOU HAVE TWO MONITORS:
It might be thinking you have two monitors connected, and is displaying a second screen, like it would if another one was beside it, which would only show the background and mouse if not set to show anything.
Right click and go to Properties, and then to Settings.
Hopefully if you are lucky since only 1 screen is running, the box should appear on the screen, and not on one thats not there (won't be good).
Here, you'll see 2 monitor screens most likely in a box, with a little drop down.
Try moving the little monitors across, swapping them, so hopefully your monitor will display the right screen, or use the drop down list to select the right monitor.
If you press Apply and it works then great
Then, go into Advanced Properties, and to Monitors, and make sure it knows you only have 1 monitor installed.
I hope this helps.
*EDIT*
Plus, if people have complained about this issue, it won't be the card causing it, since the cards working. It'll more than likely be the drivers not setting right.