It's a comment from the olden days, but make sure your Analog phone is set up as ANADTMF and it's not trying to pulse dial. It should not make any difference these days, but you could also try reversing the polarity on your cross connect.
Those are the first 2 things that come to mind unless it is a COS or LSCRCOSV permissions issue.
Don Bruechert, Voice Comm Analyst II
CareTech Solutions @ Holy Family Memorial
Manitowoc, WI, USA