I mean, the flashing command example on maemo wiki is like this:

flasher-3.5.exe -F RX-51_2009SE_2.2009.51-1_PR_COMBINED_MR0_ARM.bin -f -R

I suppose you use a global firmware version, so you need to download the file RX-51_2009SE_20.2010.36-2_PR_COMBINED_MR0_ARM.bin (PR 1.3) and then change the command to:

flasher-3.5.exe -F RX-51_2009SE_20.2010.36-2_PR_COMBINED_MR0_ARM.bin -f -R

P/S: You can check on a linux PC even without backupmenu installed, as I mentioned in my previous post, with this