wm6.5 auto hard reset issue

[akram85s]

hello experts
i want to explain my problem here and i hope that i could find any help
my htc tytn ii worked for 1 year in a perfect condition
but the problem happened when i tried to upgrade the rom to wm6.5
everything was fine tell the device frozen and i pushed the reset button
the device hard reset instead of soft reset
that happens most of times i try to soft reset (not every time)
some times it happens even if the device is not frozen
it is completely random every time defferent software, cooked rom, hard spl, radio version
every time it hard resets automatically.
am i have to go back to wm 6.1 (i hope not)