I did try strace/truss/gdb, but nothing struck me as obvious.
I tried running from the command line and CGI very early in trying to solve this and forgot about the output. Which may be more useful because it probably means this isn't strictly a mod_perl issue.
Here is the error I get using CGI (non mod_perl):
I think that if I can get this working under vanilla CGI, then mod_perl will work aswell.DBD::Pg::st execute failed: PQsendQuery() -- There is no connection to + the backend. at /usr/lib/perl5/site_perl/Apache/Session/Store/DBI.pm + line 65.
Thanks for the help,