How/Where are you preloading the modules? Are you using Apache::DBI? If you are make sure it is loaded before any DBI calls including the loading of.
#deny from all
allow from all # adjust for your IP
and preload Apache::Status BEFORE Apache::DBI, if you haven't already.
That will allow you to confirm that Apache::DBI is caching the DBI connects and you can see what modules are loaded into memory.