Anyone set it up yet with no probs?

I followed a guide on the RoR wiki and it sorta works, but everytime I actually try and run a test app I get

Application error
Rails application failed to start properly

any ideas? using fastCGI... this is my httpd.conf entry as it is

<IfModule mod_fastcgi.c>
FastCgiIpcDir /tmp/fcgi_ipc/
AddHandler fastcgi-script .fcgi
FastCgiWrapper On