Funny, i was just about to post a very similar problem.
Mine is doing the exact same thing after around 1-2 months use. Tilting on the slightest angle makes the signal drop out altogether, or cause it to flicker and distort when it comes back on. Hell, even going over a bump makes it flick off.
This is my first indash screen and it hasn't been subjected to any rough treatment so i have no idea how it's broken already.
I have e-mailed Xenarc tech support with this issue (and one or two others) and am awaiting a response. I will keep you posted.