Just wanted to let you know that I'm experiencing the same malady with the Adventure Display.
I fly mainly the PMDG 737 6/700 although I do have the 8/900 upgrade. Text in the Adv box flashes then disappears. It can be turned on and off with the "L" key (all lights on/off) but it seems to be unstable even not hitting the L key. Often now when I open at the airport the dialog box is not visible at all even though the ADV Disply is checked in the menu. If I uncheck it and check it again it does appear but also with the green text band. Now I must reset to clear the green band.
I tried it with the stock 737-400 and it looked like all was fine but within a few minutes the dialog box was blank.
I even reloaded RC. . . same results.
I think this started about a week ago it seems. I did add FS2Crew.
I'm using an nVidia FX5900XT card.
Thanks - Terry