Suunto Vyper failure

I had an interesting experience yesterday, would like to see if anyone else has experienced similar.

The dive: the dive plan was to drop on the Mercedes I wreck in 90' off Fort Lauderdale, and do a short tour of the site. From there our team of 4 Gavin divers would scooter shoreward to the wreck of the Tracy in 70' (distance approx 1/2 mile, maybe a bit more)where the boat would meet us. Total BT ended up as 75 minutes, including short deco.

On descent I checked all instruments and all were acting normally. My 3 depth/BT instruments (including Suunto Vyper) were in close agreement as to depth and time. At 21 minutes into the dive, just as we were preparing to leave the first wreck, I again checked my instruments. 2 were normal but the Vyper was showing date and time, not depth and bottom time. It had apparently surfaced without me!

I pushed the main button and it again realized it was diving. Depth came into line with reality but BT started all over again. The unit operated normally from this point throughout and after the dive.

About the Vyper- wrist mount Vyper, bought new in May 02, 36 dives on it. Gauge mode. Battery shows full, then and now. On downloading yesterday's data the first part of the dive is not shown (in other words it didn't really think it surfaced and count it as 2 dives, it totally lost the first 21 minutes).

Anyone had similar experiences with this type unit?

WW

Addendum- the Vyper was on my driving arm. vibration?

Maybe the water pressure from the scooter confused it, or maybe, just maybe an air pocket got trapped on the contacts and the vyper thought it was high and dry somehow. I'd check the battery compartment and make sure no water had gotten in there. I guess that could also be a possibility with it inline with the water pressure from the scooter. There's all sorts of explanations. What other instruments were you using? I guess its just a good policy to have a backup always. A depth gauge and cheap waterproof watch will do. The vibration could also definately be a cause since it was a sustained vibration. I'm sure these weren't designed to put up with too much vibration. Shoot an email to suunto and see what their take on it is. Something definately made it think it wasn't underwater anymore.