[Typo3-dev] mysql error in BE List module

[Christoph Koehler]

Hey all,

I just encountered a weird problem. I get a mysql error in the List module  
of the backend that is caused somehow by the extension I am working on  
right now.
The error is just a simple:

Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result  
resource in D:\xampp\htdocs\typo3\typo3\t3lib\class.t3lib_db.php on line  
754

So there is something wrong with a database query. The error disappears  
when I uninstall the extension and reappears when I install it again. I  
cleared all cache, typo3temp stuff, database tables, so it's not that.

Does anyone know what could cause this?

Apache 2.0.55, PHP 5.0.5, MySQL 5.0.15 local install with xampp.

Thanks!

Christoph