BB Storm :: Its Rebooting Randomly - How To Stop It

i am now on the 3rd Storm in as many weeks. Each one suffered the same problem. Random reboots/restarts.Phone 1 was the worst - I purchased it as a 2month old used unit. I wiped it clean at purchase and setup for my use. I did not enable Blackberry services with Vodacom for 2weeks. In that time it behaved with no problems. A day after enabling BB Services with service provider the random restarts would happen. It was primarily during BB Messaging, but was not limited to that. It would restart during calls. Other times i would pick it up off desk and see that it restarted. (pin was requested).There were times that it would restart 3 to 4 times in succession before eventually "stabalising"i visited Vodacom and was told that all Storm 2's before Mar 2010 were recalled" I was given a replacement unit.Phone 2 - Service Provider configured phone for me and restored only contacts. emails and messages. Next day restarts began. Display goes white and error message displays for a few seconds. Then phone restarts. It would reboot totally randomly. Taken from pocket. whilst driving, during a call, laying on desk. Vodacom gave another unit after testing it for a few hours.Phone 3 - Only contacts restored. Original OS and settings used. Random restarts 3 times in one day as with phone 2. It however seemed to be "worse" at certain location "my office".A technincian suggest setting to 2G only. This worked okay for 2 days and then i took from pocket and it had restarted.Event log just said powered off and powered on. No error message.This is a day later and no more reboots. But phone still on 2G.I see that restarts/reboots are common place with the Storm2 and wonder if it is a design fault.i am gonna re-enable 3G and watch again.