asterisk users - Jan 2012 - odd disconnects with major company's voice recog

Here is a weird problem that I have had several reports on lately.
Customers using our 1.4 based product placing calls to large companies
(two examples - AT&T and ComEd, numbers for which I will provide below)
that have auto-attendants based on voice recog get disconnected - by the
remote end - when the "transfer to an agent" occurs.  The message they
hear just before disconnect is that "your call cannot be completed from
this calling area".  We send all US 800 numbers via Vitelity, and I
somewhat suspect the problem may be there, because the same customers
call the same numbers from cell phones and have no issue.  Perhaps
Vitelity or its upstream is being asked to make a transfer that isn't
possible?  I haven't opened a ticket with them yet... my next call.

Anyway, I am interested to know if others are experiencing this in the
US.  Try to call AT&T at 877-722-3755 and say "agent".  You will
hear a
few DTMF tones, then either it will ring an agent or you will get the
"cannot be completed" message.  Also ComED (electric company in the
midwest) at 800-334-7661.  Hit "2", then say "agent".  A
different voice
on the "cannot be completed" message, but the effect of course is the
same!

Cheers,

Jeff LaCoursiere
SunFone