PHP4, Drupal 5, Civicrm 1.7
All went well except after install civicrm failed to find files/civicrm/upload It was missing the prefix and kept trying to create /upload in my servers root directory.
After grepping the code I found CIVICRM_UPLOADDIR and when I defined that in my civicrm.settings.php file everything was happy. So either there's a bug in there that is missing the prefixing of the upload/ directory OR civicrm.settings.php.sample should contain the default definition.
I have updated the Drupal Install wiki to add in this missing define