The problem you had is that you flashed an old firmware image (PR1.1 I think). With one of the updates (PR1.2) Nokia updated the cell modem firmware which meant if you tried to run a old version the phone functions wouldn't work.

You have now flashed PR1.2, but PR1.3 is the latest firmware image, so I would recommend flashing again, the file you want is "RX-51_2009SE_20.2010.36-2_PR_COMBINED_MR0_ARM.bin", then once you've done that you may want to considered updating to the CSSU which is some updates and bug fixes provided by Maemo community developers.