options-general.php won’t load (wp 2.6)

Hola.

I just upgraded to 2.6 and have also upgraded all used plugins. I’m trying to add another (Category Cloud) now but after activating, when I go to the Settings page it won’t load – no error message, just a blank page. Any ideas why this might be or how I can find the cause? I use about 30 plugins so deactivating one by one is a slow process.

Thanks!