Hmm. What happens if you drop the
`<IfModule mod_rewrite.c>` (line 134) and matching
`</IfModule>` (line 178)? I seem to vaguely recall that sometimes certain rules are available in Apache but the IfModule checks fail. May be a long shot though.
Commenting out, or just setting the
`true`, is a good way to test things for sure. That constant is defined by an environmental variable in the
`.htaccess`  so forcing it yourself when you know the file exists and is picked up by the server is OK.