I have the latest version of WP and the latest version of WP-T. I double checked to make sure all my keys and info were entered correctly, and turned off URL shortening just to avoid any errors. It doesn't seem to be posting to Twitter at all- instead I get the message saying its being stored into a custom field. When I click "Check Support" I get a message "WP to Twitter failed to submit an update to Twitter."
I see some other people here having some similar problems, so I'll check back in a couple days, thanks :)