WordPress, and Server Error 500

Like others, whose webhoster is 1and1 and who use WordPress, I experienced a lot of problems with some very popular plugins, such as qTranslate or NextGen.
After activating the plugin, an

Internal server error 500

occured whilst using the admin panel, even preventing me from deactivating the plugin. In this case, there’s only one option left: connect via FTP to your webserver, change directory to your WordPress root, and in wp-conten/plugins rename the plugin directory. This way, WordPress won’t find it anymore and will deactivate the plugin automatically.

But, of course, there has to be a workaround, instead of simply not using certain plugins. The following activates PHP5 on your webspace and worked out perfectly for me:

  1. Open (or create) a .htaccess file in your WordPress root.
  2. Add these lines:
    Options All -Indexes
    AddType x-mapp-php5 .php
    AddHandler x-mapp-php5 .php