I have same problem.
After playing an instant action with say the A-10C, then jumping in an F-15C in the same instance of DCS, the exported monitor (VSD in F-15C, or L/R MFCD in A-10C, or Shvkval in 25T - doesn't matter what the exported screen is), becomes TOTALLY unusable. It looks like several backdrops overlayed on one another from previous instances of DCS in-game backdrops to the point where you can't even see the sensor image that is supposed to be displayed. I have attached an image showing you my exported MFCDs. The left MFCD is supposed to be displaying the VSD, which it would be if I jumped in after freshly starting an instance of DCS. However, if I exit a game, then re-enter, this is what I am getting:
http://imgur.com/3fZFOOh