I installed a new version of MAMP, and then my Views PDF pages weren't loading. Got a server error.
The php_log kept saying "PHP Fatal error: Cannot redeclare drupal_error_levels()"
So... I went to MAMP, Preferences, and changed cache from from XCache to eAccelerator. Now it generates the PDF.
Hope this helps someone. Wasn't quite sure what category to put this under.