I was using AuthImage – Keith McDuffee’s fantastic WordPress plugin to prevent comment spam. I wrote about the process which led me to install this plugin last year.

Recently however, I realised that there was a problem with the plugin – it wasn’t displaying the code for commenters to enter, so no-one was able to make comments on any of the posts in this blog.

To find the error, I accessed the authimage.php file directly asking for an image (i.e. authimage.php?type=image) I received the error “Call to undefined function: imagettftext()”.

A quick Google on this error led me to a page which explained that “Those errors indicate that your PHP installation does not have True Type Font support compiled”.

I contacted my hosting company explaining the problem, and they responded quickly with a mail saying “I’ve rebuilt php with the required modules. All should be fixed” and indeed, AuthImage is now functioning as expected again.

Interestingly, I disabled the AuthImage plugin when I spotted the problem, and in the few short hours that it was disabled, I received a load of comment spam. This was the first comment spam I had received since I had installed AuthImage. Just goes to show how effective this plugin has been in stopping this plague annoying me!