I have this problem on Wipeout HD's online for both the normal game and for FURY. Whenever I try to get into an online match on my main account it will say "error user is already signed in" and then I can't play. I've tried using three different systems, none of them will work on my main account. All PS3's will work with my second and third account. I've tried to delete the game and re-download it again multiple times now but that doesn't work either. I called Sony and the worker told me to format the PS3, now I have a PS3 with only Wipeout, it's the only game, and it is still not working. I called Sony again and they told me to make a post. Can anybody offer any suggestions?
Also, none of my friends in Europe have this problem.
This seem to be a problem with either: the Whipeout HD servers or its gamesave files.
I have found several threads with many scenarios like yours; scenarios in which the user has successfully signed into the PSN, started Wipeout HD, selects the Online option to just run into a network error. Network errors range from "failed to load players list" to "user already signed in."
Solutions to your particular problem, all with different success rate, include:
The second option isn't so much of a solution as it is a "remedy" It wont solve the problem for good but might be able to get around it. Alternatively, instead of "signing into the PSN then running the game, logging out, access wipeout hd online, then sign in;" I would just "run the game, try to access wipeout hd online and when prompted by the system then I'll log into the PSN.