To be honest, I am not all that familiar with Test::MockObject, as I have yet to find a situation to use it in. Am I right in assuming that you are using Test::MockObject::Extends to mock parts of Class::DBI objects? Or is it to mock other objects?

One possiblity might be to move your mock objects down a level, and use DBD::Mock as a faux-database, rather than mocking Class::DBI (if that is indeed what you are doing)? This would allow you to use Class::DBI as you would normally. Personally, I like to mock as little as possible, and as "low to the ground" as possible (database, network connection, etc.).

But I am just making assumptions here, if you want to provide more info about exactly what it is you are trying to do, I might be able to help more. And of course you could always try messaging chromatic, since he is the one who wrote Test::MockObject in the first place.