Today at the St. Louis Region autocross my MPx200 was sitting out, underneith a cold cup of ice. I've had problems at the past few events where the phone gets hot in the sun and the front panel goes dark. Today that started to occur, so I sat the phone under the cup for a while.
When I picked the phone up I noticed it was vibrating off and on, so I thought I had a call, nope, no call, and no SMS message. Weird, so I sat the phone in the seat of my car. I picked it up a few minutes later and it was vibrating again, but this time it won't stop. Both displays are now off, I didn't turn off the phone. I try turning the phone on/off and nothing, it just keeps vibrating. I tried removing the battery, it stops vibrating, of course :) I put the battery back in, starts vibrating again!
I tried multiple things, holding down the power key, holding down the blue button when inserting the battery, holding down both. I couldn't get it to quit vibrating or power up.
I ended up leaving the battery out of the phone for about 10 minutes, and then when I installed it again the vibrating stopped, but the phone wouldn't start up.
After letting the phone sit again for a while it finally started up. I was beginning to get afraid I was going to have to do a hard reset again. Luckily it all appears to be back to normal now!