Yep, kind of.
I had an issue where I once didn't know that I would get the authentication widow and I closed miranda under the impression I had missed something (to input the SteamGuard code into). When I started miranda again and tried to connect, I never got the authentication window again.
To solve this, I logged in to steam from the actual application and revoked login permissions for all of the authenticated connections. Upon next miranda login, I was presented with the steamguard input box again and this time I didn't miss it.
Can you somehow revoke authentication of your attached twitter devices? It may be worth a shot.