Blank admin page after installing a module or translations

Hey everyone, I always get a blank admin page on /admin after installing a module or just now also with a translation.
I have no clue on how to solve this.
I tried this:
http://drupal.org/node/31819

changed memory_limit = 32M
, after I deleted the module from sites/default/modules
it works again, but I dunno how I can undo the language pack.
And it's quite iritating not being able to try out any module?
I made sure it was for the right version 6.x each time

I'm using xampp to test locally.
Any clues?
Using Drupal 6.10 now and had same problem with 6.9...

Thanks in advance.