I followed all of these instructions to downgrade my wife's rooted 2.1 and it seems to have worked fine. I've got it back to 1.5. She wanted the OTA upgrade because the 2.1 rooted version was giving her the silent call issue. Again, I went back to 1.5 because I wanted the OTA update. After doing this, she got the OTA update notification, it downloaded, processed and then failed. I've also tried to install the OTA manually and it won't work. The hboot is version 1.47. Has anybody had success downgrading their 2.1 rooted install to 1.5 and then getting the OTA update to work? I'm back at 1.5. What should I do next to get the OTA update working? Thanks!