I've experienced the same issue like you with my 9530 from verizon. It's suddenly restarting into a boot loop while i'm texting and nothing could be done to fix it. My friend's 9550 also died suddenly in one morning and couldn't be fixed. After i've lost my 9530, i bought 9500 and that thing still working fine eventhough i've replaced the screen 3 times because i cracked it. That's why i switch to 9860 rather than 9850 because from what i've experience it by myself and from what i've read in the forums, blackberry devices that works in CDMA such as 9850 have the sudden issues a lot..