Actually, turns out my CGI::Application was something entirely different...in trying to reduce it to a test case, I found a new problem! Grr..

Anyway...main problem was that under CGI::Application::FastCGI, I was not releasing the database connection (was no need under normal CGI, it just released itself...), so then trying to recreate it failed miserably.

So...thanks for your help, think I'm all sorted now.
Jay