>>>>>Dear all;
>>>>>
>>>>>After almost 2 years, one of my applications is not working…
>>>>>This particular one has a button which makes telephone calls using MSCOMM (AT commands)
>>>>>So far, so good. BUT! Until now, it wasn’t necessary to dial numbers with more than 10 digits (US standard). Now they have to call 1-800 numbers (11 digits), and mi “dialer” doesn’t work! (Your call cannot be completed as dialed….) I verified the numbers, all valid.
>>>>>I thought it could be the switchboard, but if you dial manually…it works fine, so, I have not idea what’s going on.
>>>>>Any help on this?
>>>>>Thank you,
>>>>
>>>>I haven't used MSCOMM for dialing, but try putting in a comma or two after the "1", before the "800". A comma is a 2 second pause for AT commands.
>>>
>>>Thanks for your answer, I have tried (in advance) your suggestion, the same....
>>>In fact, I tried putting commas everywhere! Nothing changes. This is really weird.
>>
>>Are you sure you're not on a PBX that requires you to dial "9" or something else first to get an outside line?
>
>Totally sure. As I said, If you dial manually it works.

That's not necessarily any indication. Some phones can be programmed to dial the "9" (or whatever is needed) so the user doesn't have to do it.