and now I can't get my galleries to work anymore. I wanted to add the lines described in one of the watermark topics to it, but it now seems I didn't do it correctly :( Is there a(n easy) way to fix this? Or should I reinstall everything again?
Can you log into your gallery admin? If so, go to Options and uncheck the box next to Generate Cruft-Free URLs. Then create a blank file locally and save it as .htaccess. FTP that file up to your server into the folder where you have Plogger installed.
If that doesn't work, then you need to log into phpMyAdmin, go to the database for your gallery. Find the table called plogger_config, click on the Browse tab within that table. There will be one entry in that table. You want to edit that entry and change the value in the column called use_mod_rewrite from 1 to 0. That will disable clean URLs and you should be able to access your gallery again.