i know you asked this question nearly 3 years ago, but if you're still using MX, and have stopped it from crashing, but haven't figured out how to deal with the "marquee" problem, as you put it, what worked for me was turning off the windows aero effects by changing to a windows classic theme. You probably figured this out already, but I'm just leaving it out here.
As for the crash, I'm not sure; it looks like something was wrong with the dll file? authplay.dll is in the First Run folder. If this happened to me, I would try uninstalling MX then reinstalling it, just to replace that file. I use windows 7 as well but have never had it crash like that before.
Anyways, sorry for the super late reply and I hope it helps (you or anyone else).