Your dialing rules are not being applied to Windows 2000 applets, such as Phone Dialer and Fax?
When you enter a phone number for these applets, you must use canonical form:
+Country/RegionCode (AreaCode) SubscriberNumber
To enter a phone number for a North American subscriber, use +1 (123) 456-7890.
From the Windows 2000 help file:
Canonical address format for phone numbers The canonical address format is a universal phone number format recognized by the Windows Telephony API (TAPI). Some address book programs store numbers in this format. If a number is not being dialed correctly, you may try saving or entering the number in this format. The format explicitly identifies the components of a phone number, which TAPI translates according to a country or region's dialing rules. The canonical format is: +Country/RegionCode (AreaCode) SubscriberNumber For example, this is how you would enter a number for a subscriber in the United States of America in canonical format: +1 (425) 555-0100 Components + Indicates that the number is in canonical format. Country/RegionCode - The standard country/region code that identifies the country or region for a phone number. This contains one or more digits from 0 through 9. The country/region code is delimited by the space that follows it. (AreaCode) - The area or city code for the phone number. This may contain one or more digits from 0 through 9 and is delimited by parentheses. This component is omitted for countries that do not use area or city codes. SubscriberNumber - The number for a phone subscriber. This contains one or more digits from 0 to 9, formatting characters, or the dialing control characters: A a B b C c D d P p T t W w * # ! @ $ ? The subscriber number should not contain the following characters: ( ) ^ Formatting characters in the subscriber numbers are normally spaces, periods, and dashes. Use formatting characters to make a phone number easier to read. They do not affect dialing, because TAPI discards them.