Threading fixes

Hi,

First commit about list() should be ok as it is, atleast as far as I know.

The second one, I don’t really know the cause, or how this really affects, but it did get me a bit further. I’m having some strange threading related problems, which mostly are just due activerecord being not really multithreading compatible, but some strange NPEs and other errors too. So I decided to include this fix too.