Thanks to entodoays I managed to fix my reader! Followed the procedure to make partition by partition backup of working unrooted device. Restored partitions 1,2,5,6,7,8,9,10 on my faulty reader (did not delete the partition table, diff showed that my partition table and partition table from working reader are identical). End voila, everything worked, problems with dictionary are solved. Rooted with latest package and still everything is working.
I then also rooted working device (since I have full backup). Checked the diff between dumps of un-formatted space and yup, there is some difference, so root-ing will change that part of FLASH and YOU SHOULD DO BACKUP. To bad I did not do it for my faulty device but now it should not matter.
My faulty reader has some bad blocks in un-formatted part of the flash. Probably that caused the errors. My speculation is that during the factory reset part of the information from un-formatted partition is written to some other partition. It's a very speculative guess though...