We'll defer to them. We have a whole page devoted to this one. I have voice mail and I can't dial when I have messages. Modems aren't very smart that way. You can have your modem ignore dial tone and dial anyway by changing your modem init string.
People hate things dialing in their ear.
To modify your modem init string to ignore dial tone, you just need to add X3 to the end. Click the little arrow at the lower left so the window drops down. Click the Accounts tab. Click the Connection tab. Add X3 to the end of the modem string shown.