To clarify...are you talking about a "1" showing on your incoming caller ID, or your outgoing caller ID. You mention it happening on some numbers, but not others. If it is incoming, then your CID re-formatting should take care of that if there is a leading 1. If you are talking about outgoing caller ID, then the forst thing you need to confirm is whether or not you are actually sending it (on some numbers?). If you are not, then it may be that it is being added by your provider, or, the provider of the recipient.