RT::Mason errors

Can anyone offer any insight into what would cause these
errors on RT?

Aug 14 17:17:37 doccomm RT: Use of uninitialized value in -f at
/usr/lib/perl5/vendor_perl/5.8.8/HTML/Mason/Resolver/File.pm line 74.
Aug 14 17:17:37 doccomm RT: [Mason] Cannot resolve file to component:
(is file outside component root?) at
/usr/lib/perl5/vendor_perl/5.8.8/HTML/Mason/ApacheHandler.pm line 853.

We were successfully running RT 3.6.4 on CentOS 5/Apache 2.2.

To do some testing on Apache 2.0, I installed it into /usr/local/apache
along with mod_perl 2 from source. It inadvertently installed stuff
into the /usr directory despite my setting prefix=/usr/local. So I
subsequently did a ‘make uninstall’, an ‘rpm -e mod_perl’ and then
reinstalled via yum in an attempt to get things back to original and it
seemed to do so.
But ever since then, RT won’t work (I get a 404 Not Found error)
and these messages end up in /var/log/messages. I’ve tried to debug
what’s wrong for a couple days to no avail. I don’t think it’s RT itself
as I can rename the RT_SiteConfig.pm which I know would make RT barf and
the error is still occuring. The only thing I changed in RT or Apache
was this line in RT_SiteConfig.pm to get RT to use $REMOTE_USER for auth.

Set($WebExternalAuth , undef);

Thanks for any help.