DSL connection problem?

Today SBC came to fix my connection and told me my modem needed to be replaced..the last few weeks i had been experiencing bad connections [apparently ping problems] well they fixed it today and i bought a 2wire modem [i hooked up another home computer with dsl] anyways,as i type,it's still having those problems..where there is a connection and it all of a sudden goes out within seconds..i'm not talking about the modem,the modem actually doesn't even blink red...but it does go out..i checked my technician readout and it says all is ok..what is going on? I am especially affected whenever im answering questions on here,where i post then i go back or something and nothing loads...any help??? what could it be?