Anyone know of a patch, workaround, or update for a BCM 200/400 unit that is similar to what Release 3 did for the BCM 50s?

I am configuring SIP trunking on a BCM 200, but even with the most current patches there are still some crucial SIP options missing. The main problem is with DTMF tones being not present because the BCM is not speaking RFC 2833 (the SIP DTMF signalling standard).

Currently running BCM 200 software 4.0.21.d with Feb 2010 Smart Update patch applied.

Any thoughts appreciated.