this issue can behave differently on different phones, even the same phone, so the fact your wifes phone is ok and yours is not does not really mean your phone is defective. lots of factors in play to cause a device to freeze or misbehave...
it is worth a shot to contact phone support at sprint and maybe get to tier II to have them make sure your account is setup properly.
you could also be in areas where network vision is still rolling out/being upgraded and what you are experiencing is temporary growing pains.
the original evo on wimax did the same thing in areas where 4g and 3g would toggle. a workaround was to go into the phones radio settings (using your MSL) and altering radio thresholds and sensitivities and timeout values to squeeze every bit of wimax 4g one could find.
so just monitor where you are and the signal coverage when this happens. also if you know of areas where this occurs, temporarily disable 4G and see if the phone locks up. this should give you an idea if its just 3g/4g flip flop or not.
if you think your phone is defective and you are within your 14 day return, take it back for another.
Originally Posted by spthomas