Edges briefly flash in center display

[bkc]

Hey all. I've got a 2007 E320 CDI. Every now and then the edges of the center display (where the system messages, mpg, current music track, and so on show up) flash. It is a series of white boxes around the edge/ring. It only does it for a split second. It actually took me several days to be sure it wasn't just a random reflection, but today I caught it enough to see the boxes, like a checked pattern around the edge. Didn't see anything in forum or web searches, although I could be using the wrong phrasing. I only have noticed it shortly after start, usually the first start up of the day. Any ideas? I'm going to be going on a three week road trip, so would especially like to make sure it isn't something that will strand me!

No codes that seem even remotely relevant (using Autel MaxiSys Elite). Car glows and starts instantly, everything seems to work fine.

Thanks!
-Bruce