I have the same issue...I also had been putting my BB in my pants, my ski pants to be specific (inside a ziploc bag). I snowmobile with it that way and had done so all season with no issues. Last week, I took it out to take a picture of a buddy who wiped out and the "white screen" thing happened. I did a battery pull, then signed back in.
I've also noticed the LCD is getting some weird pixel issues from time to time. Not sure if I warped the LCD somehow, but it seems to do it off and on. If it keeps up, it's time to have the IT gang "fix" it which generally is a dump, wipe and start over, only to have the same thing happen. 99% of the time I carry it in the holster, but I may have done some damage in the pants.
Keep me posted on if anyone finds out the cause.