[Mark Rejhon]

2 out of 2 success rate so far!

1. Backup your SD Micro memory card to a folder on your computer
2. On the copy on your computer, delete all "BBThumbs.dat" files in all folders
3. In your BlackBerry, REFORMAT your SD Micro Memory card.
4. Copy your memory card contents from your computer back to the SD Micro memory card.

If you've got internal memory, do the same for your 1 gigabyte of internal device memory. Although that really can't be reformatted, you should be able to least delete the BBThumbs.dat files in this 'memory' too by accessing this in Mass Storage mode. Alternatively, you can temporarily set aside the memory card and use a different SD Micro card and reformat it.

I suspect RIM must have improved their filesystem scanner speed, and there's some stability bug in the filesystem scanner (and the .dat files appear to be some kind of fast thumbnail-index files on the memory card). It has happened before in varions versions of OS 4.6 likely because some optimized-performance thumbnails reader crashes when reading corrupted BBThumbs.dat files.

Besides, starting afresh actually improves the thumbnails performance after the initial lengthy scan. Also, your BlackBerry may be slow for a few minutes while the scanner is regenerating the BBThumbs.dat files in the background. But then you'll have a fast and stable BlackBerry afterwards.

Anyway, it seems to stabilize at least one cause of 5.0.0.314 random reboots.