I had same problem on leaked PR1.2, dont know what was causing it but i disabled maemo repository and added new one with same settings changing only distribution from "fremantle-1.2" to fremantle only and that was it, conv widget worked again....
I tried this about a dozen times now including rebooting between install and uninstall and I still cant get the damm widget onto the desktop. It was working fine in the unofficial release.
Sorted now thanks wildone. It needed the 1.1.1 update