trademark infringment

while recentley surfing the web i discovered that a former member of signed and established major national band had started another band, the name of this band just happens to be the same name we've been using for 5 yrs now they have not released any music to date but having major industry ties we are concerned that we will be unable to stop this from happening we have a demo cd registered with the library of congress dated in 2000 this being the only federal documentation we have we believe that this along with our merchandise, fan base, dated photos, video tapes of past venues and logo could make us able to file a letter of infringment with the trademark office do you think this is possible?