PPCGeeks - Phone lockup

My phone has locked up on me three times now and I "think" its happening in areas where there is no signal. The first time it occurred was while on a trip to visit my girlfriend in a area I recalled having practically no reception as my calls kept dropping instantly in that area with my previous phone (Samsung SCH-i760). On the way back, it locked up again in that same area. Both times the green power light continued to blink. I didn't have any issues after that for about a month until today while I the way to a store. I pulled the phone out of my pocket while in the car and it was locked up. The green power light was still blinking as in the other two cases. I'm starting to really think I'm hitting some dead spots that are just completely locking the phone up as it tries to find a signal. My Palm Treo 700p would always act fussy in areas where I couldn't get a signal as well. It wouldn't allow me to turn the screen back on until it found any sort of signal again.