Presence of php.ini causes wp blank page

I have been trying to increase the PHP memory limit for wp, and have run into a problem.

I can add a php.ini with memory_limit = 64M;, and testing it with a phpinfo() shows that it works, and indeed other php pages I have work fine.

Not WordPress though.

After a lot of mucking about, I have found that the mere presence of a php.ini file causes WP to display a blank page. ie: Even if the php.ini file is empty, WP fails.

Does WP inspect the php.ini file? Does it expect a certain format?…or perhaps permissions?

I can’t use the .htaccess for php_value because suPHP is enabled.