6
I've had exactly the same error - Install XOOPS, configure, works fine, switch off overnight and when I came back to it the next day this showed up.
So I reinstalled and tried again and everything was fine until I switched off. Now I know I'm just messing around at the moment with a WAMP environment (EasyPHP on WindowsXP home) to provide a demo to a client, but this was getting annoying.
The problem turned out the be the ZoneAlarm firewall I was using on my PC. Even though every Apache/MySQL/PHP process was allowed to do whatever it wanted, unmolested, it would not physically connect until I had turned Zone Alarm right off.
Don't know if this is of use to you, but it might suggest some more options for you to try.
Best Regards,
Gareth