DTMF stopped working

Dont know why ,

I am using asterisk now and have upgraded to asterisk 1.6.2.6
when i call outside and need to send DTMF (for an answering machine etc…)
it seems thatmy dtmf signals are not sent on the sip line.

it used to work and i think upgrading broke it…

anyone have an idea on how should i debug this ?