11.24 - Bad Syntax during Apache Global Configuration

Recently upgraded to 11.24 (and jolly good it is too so far), but one problem I'm experiencing is that when using the Apache Global Configuration option under Service Configuration -> Apache Configuration, I get the following errors upon saving the new config.

I've looked at the httpd.conf file itself, tried rebuilding it with /scripts/buildhttpdconf, and the same problem occurs. I can't see anything obvious.

Code:

Rebuilding httpd.conf...

Initial configuration generation failed with the following message:

--- Syntax Not OK ---

Rebuilding configuration without any local modifications.

Failed to generate a syntactically correct Apache configuration.
Bad configuration file located at /usr/local/apache/conf/httpd.conf.1225469761
Error:
--- Syntax Not OK ---

Yet Apache restarts just fine - but no changes are actually made to the Apache configuration file.

I don't think I've made any manual edits to the config file in the past..