Brake Auto assist automatically coming on

On my 98 Breeze, recently when I am accelerating and reach about 40mph, my brakes come on all by themselves...if I let the car slow down, then at about 20mph they release....Does anyone know what could be causing this?

Please Help!!!

Thank you,

Steven

P.S. This is only the newest of a few problems...I will start thread on the others...

Do you know for a fact that the brakes come on or does it just feel that way?