Wont wake up so call can ring!!!!!

[zaya]

I just noticed this tonite and hope it hasnt been going on for too long. When my Mogul is "asleep"(screen off) and someone calls me, it will not reactivate itself so thier call can ring thru. Only once i have missed their call and press the power button then i have a notification saying i missed their call. but it never rang. I did a soft reset and it is working fine right now, but I cant risk this happening at random. Anyone ever heard of this issue and possibly a fix? Thanks in advance.