Hi folks, I just ran into something - bad blocks on the internal flash drive - and the dictionary partition was affected on my PRST1!
This could definitely cause freezes, too!
My dictionary partition had more than 100 bad blocks

Fortunately, rupor has a backup of the dictionary files:
http://projects.mobileread.com/reade...rupor-dicts.7z I extracted them manually and copied them over the broken ones after marking all bad blocks. (Applying the flash package would make the reader forget about the bad blocks, so beware!!!)
I updated the wiki on how to scan for file system errors:
https://wiki.mobileread.com/wiki/PRST...and_bad_blocks