OK, I have another operational question. Where do you guys leave the fuel selectors while parked? Do you turn them off?

I am still getting to know my new Seneca II but am suspicious that there might be fuel flowing from the right tank(s) into the left tank(s) while the airplane sits. I've been leaving both fuel selectors "on"; the POH doesn't say anything about switching them off after shutdown. Perhaps my fuel control valves need some servicing, since in theory there shouldn't be any path for fuel to flow between the wings.

Any thoughts here?

Thanks,
Dan