After installing Drupal 6.2 and enabling the Citation Filter module (/sites/all/modules), I went to Input Formats / HTML and checked the Citation Filter box. Immediately, I got this error: Fatal error: Call to undefined function: stripos() in /MYPATH/MYSITE/sites/all/modules/citation_filter/citation_filter.module on line 45. The only way to address this was to delete the module on the server.

Since this site is still pretty vanilla at this point I have to wonder, are there other module dependencies? Or perhaps this module needs to reside in the core modules directory instead of /sites/all/modules?