Losing signal with mini display port to vga adapter

Was this a problem form the get go? Or did it show up later?

If this is a new adapter I would return it to see if the adapter was bad. If it was working and then started up to be a problem then it could be any of the pieces. Try plugging in a VGA display to see if you can isolate down the problem. Does the display react the same way? If not then its the projector, if yes then you'll need to swap out the cable and adapter as then next easiest things to isolate out. Lastly if nothing changes its the mini that needs service (hopefully not).

You might want to check your buildings grounding and the outlets are correctly wired. Don't forget to get a surge suppressor to plug in your gear (each system should have its own). I would also recommend you talk to your electrician on getting a whole building surge suppressor as well. Heres a good vid on what you should have if you have a lot of lightning in your area and it also talks about the whole building surge suppressor: Ask This Old House - Lightning protection