Error mysql_pconnect() when site goes live

[eluser]keld[/eluser]
Thanks Bart it worked! not sure what the pconnect is all about, maybe my webhost doesn't have this module loaded.
Anyway, my homepage shows up fine but if I click a link to go to another page I get a 500 Internal Server error, any idea why?
I used to have this error before when I didn't use ASCII mode to upload the htaccess file at the root of the folder, but I don't get why the home page would work and the others?