I feel your pain! Browse to see other threads that show other users got caught out with this too. There appears to be conflicting advice concerning the type of hosting account required.
1+1 seem to be a hosting company that WA recommend but I've emailed them to see if they can accomodate WA's updated system requirements for PS3 but I've heard nothing back from them. So, I'm at a dead end with it.
Hope you have more luck than me. Sorry.