Thank you for your answer.
So if my problem is with the file system, do you have a recommendation for a possible solution? I tried flashing restore set, factory reset and the problem remains, so this makes me think the problem is not with the system or data partitions which these two operations should replace completely. So, which other partitions could contain the culprit of this problem?
I might probably get hold of another, non-rooted PRS-T1. Assuming both have the same firmware version, which partitions are safe to copy from one to the other without risking to brick the old one?
And on linux should I backup using the
dd if=/dev/sdbX of=sdbX_backup.bin bs=512
command (where X is the partition to backup)? I read the man page but didn't quite understand the meaning of the bs option. What is the best value for this option?
I agree with what was said earlier that the problem seems to be related to waking from sleep. If I turn off and on again and try using the dictionary and the reader, I notice the bugs related to the Reader and Dictionary app (sometimes the definition box at the bottom doesn't appear at all, other times is appears only for a second when clicking somewhere else on the page) but the unit doesn't become unresponsive and I can change the dictionary without the unit becoming unresponsive.
What if it is a fault RAM problem? This would explain corrupted data being written but would it explain why the unit works reasonably well before sleep and have the tendency to crash after waking up?
Thanks a million for your help.