I have exactly the same problem. The device works fine until I try to turn on the wifi radio. Then it reboots. Once I get the wifi to work - no problems, you can switch it on and off with no reboots. To get it to work I enter the wifi connection wizard and then turn wifi on there. That seem to do the trick, but not alway work. I hope they fix this soon.
I have the same issue. I can be using the data off my network (telus) and my phone will restart like 10 times a day...when i use wifi..NOTHING!! i have exchanged my phone 4 times...my service provider suggested i reload everything in my blackberry manually....that didnt work..according to them, im the only one who seems to be having this problem! - seems to me the devices on Bell and Telus are having these problems--- anyone else as frustrated with it as i am?? RIM is starting to disappoint me..Im contemplating leaving my bb for a whole other device...i think this is totally unacceptable...its a flaw in the device that i dont think ill be able to overlook...im sure many feel the same way..