I suspect that the Suhosin patch may be causing function_exists(’quoted_printable’) on line 442 to return true.
http://us3.php.net/manual/en/function.function-exists.php#77980
Since you’re using the patch, and not the extension, you’re not able to specify
suhosin.executor.func.whitelist
in php.ini
Would you be able to do a test in Suhosin’s simulation mode? (Maybe not, again because it’s the patch.)
http://www.hardened-php.net/suhosin/configuration.html#suhosin.simulation
Do your Suhosin logs tell you anything?
It would be possible to "fix" this for you by removing that function_exists call on line 442, wrapping the actual quoted_printable() function, but I fear that we could end up with "function already declared" errors if a MODx plugin is installed and also has a quoted_printable() function.