While playing with the buttons on my Mosquito during one of the surface intervals, I have accidentally switched the diving mode on the dive comp to FREE diving. During the next dive the dive comp locked up after 5 minutes of diving, and gave me an ER message (Mosquito has a 5 minute bottom time limit on the free diving mode). When in ER mode, the dive comp will only work as a depth gauge. It remained so for 48 hours before it unlocks itself. Well, it is my own fault but still it s**ked big time, as I have to dive without a dive comp for the next 2 days....