It sounds like it is doing what it's supposed to do.
I believe Phone Dialer is meant to place outgoing calls on your land line, which then you continue with your landline telephone and talk. Phone Dialer picks up your phone long enough to dial the digits, and then hangs up, assuming your wired handset will continue the call. If you don't hook up a handset or pick it up, then the call will be ended immediately after it is dialed. They give you the "Talk" button because when you hook a handset to the "PHONE" jack on the back of the modem, you usually can't hear or talk on it until the modem has hung up the line, hence "talk" being equivalent to "modem hangup".
When you use it to dial your mobile phone, the mobile phone is the recipient of the call. The mobile phone cannot be used to continue the call.
