I've had a play around with this in the debugger and found that you get this error if the ServerRoot in your Apache conf file has quotes around it. So if you change:
ServerRoot "/usr/local/apache"
to:
ServerRoot /usr/local/apache
Then it will probably work (certainly did for me). It looks like the module doesn't take the quotes into consideration...

Update: I have raise a bug report on cpan Ticket 28717