PS3 Vault has some possible helpful tips in order to prevent Wipeout HD crashing on your PS3.
1. Sort out your buddy list – It usually works if you have 50 friends or less.
2. Then delete both the "Wipeout game" game file plus the system key * Found in system data* .
3. Go to your download list, and then install the "Full Game Key" (100kb) File first.
4. Download "Wipeout hd" file.
5. After completion, install the game then, turn your Playstation 3 system off at the back of the console.
6. Disable the screensaver option, Found in settings, on the Playstation 3 XMB.
7. Launch the game, and hopefully your good to go."