Video worked but now does not

[matwithonet]

I built a computer the other day and I had it working all day yesterday and this morning. Then when i got home 2 hours ago, my monitor says no signal.

I have a MB MSI NF750-G55 AM3 R mother board, VGA ASUS|ENGTS250 DK/DI/1G RT vid card, and MEM 2Gx2|CORSAIR CMX4GX3M2A1600C9 R for memory

 

[Tmagic650]

Did you get it working?

 

[matwithonet]

Yeah it's working now in the first slot again. No clue what happened. But is it strange that when I alt tab from a game like Wow that the whole screen goes black for like 5 seconds?