Arrgh...
Just tried flashing it. Took forever to figure out how to do it according to the various conflicting "How to" guides, but I finally thought it would work (using my Windows 7 x64 laptop).
But, as it was flashing, I executed this step:
C:\Program Files (x86)\maemo\flasher-3.5>flasher-3.5.exe -F RX-51_2009SE_20.2010.36-2.002_PR_COMBINED_002_ARM.bin -f
after flashing the eMMC seemed to complete successfully, and instead of taking 2-5 minutes as the instructions said it would, it quickly went through a list after showing
SW version in image: RX-51_2009SE_20.2010.36-2.002_PR_002
and then ended with this within a few seconds:
Raw data transfer EP found at EP2.
Using flashing protocol Mk II.

C:\Program Files (x86)\maemo\flasher-3.5>

Something has gone wrong. But I don't know what and cannot figure it out from all the threads I've been reading on the subject.

Does anyone have a clue?