No failures, and yes, the ones I pick are saved in the SD card. I have had no issues with the SD card, no unplanned mounting and unmounting of the card. One thing that has also been happening, and seems to cause some of this is that the case I put it in, bought at the verizon store especially for the DX, sometimes causes the phone to go into "multimedia" mode as if it were docked. The magnets in the case make it go to that mode. It's long and complicated... But, when I first got the case I would put the phone in the case facing inward (habit). The phone would go into car dock mode. After experimenting, if I faced the glass outward, it would act normal and remain in sleep mode, or with the screen off.
Recently, before I switched to GB, it started going to multimedia dock mode. After GB, still happening...