Xperia X8 :: Can't Synchronize With Sony Ericsson Website

I have been trying to synchronise my Xperia X8 to the Sony Ericsson website. It worked the first time when I set up the sync, and managed to copy over my calendar. However, my contacts weren't backed up on the website, so I tried again to synchronise my phone via the sync 'app' on my phone (as before) to copy them over, too, but a message kept popping up in the status bar of my phone saying 'No network access. Please try again later.' My network coverage is '3 out of 4 bars', according to my phone, so it should be quite strong. I have been trying repeatedly to sync over at least 3 hours, but with no success, and the same message keeps popping up, regardless of the fact that my phone shows a good network coverage.