The reader is up, running flashy new PRS+ 1.1.3.
kartu, thanks for your help on upgrade, and then one BIIIIIG THANKS for the work on PRS+.
This was the (failed) upgrade from PRS+ 1.0.2. The log that I copied from the reader was correct, to the letter (well, a space here or there might have been added/removed). I had the same problem when I tried to flash 1.1.2rc.
After fresh flash with 1.1.00.18040 the upgrade was performed with the same SD card, so the theory that SD card errors might have contributed is a bit shaky, but not impossible. I am off to install that dictionary.