Slow initial controller request in development mode

The initial request to a controller action seems to be very slow (around
30
seconds). This only happens in development mode and only on the initial
request after making a change in the action rhtml. I know development
mode
is slower but this looks like there’s something else going on under. It
applies to both webrick and mongrel. Any checklist out there to
troubleshoot
what’s happening here? Thanks.