been a MFish user for 2.5 years. always connects first time and is the fastest by far of the 10 or so ISP's i've tried.
have your phone lines checked out (seriously) as i had busy-tone/disconnetion issue that went on for x6 months with BT until i realised it happened across all my ISP's (6 at the time). threatened BT with Trading Standards and they reconnected me a new line at exchange. worked perfectly ever since.