Mine did the some thing a few months back when driving to work. Gear indicator flashing, stuck in 4th gear and the speedo stopped working. As soon as I turned it off and restarted everything seemed to working OK, so I didn't think it was heat related. Dropped it into the service centre but they said they couldn't find anything. The only good news is that was at 13,000kms and now at 23,000 I haven't had the problem again (fingers crossed).