Avast has had these problems in the past with DAZ installers, but they are false positives.  Avast has choosen to set itself to 'paranoid' level and throws up a warning any time anything is a little hinky looking to it.  I switched to MicroSoft Security Essentials and have never gotten a false postive or a virus.  MSE is free, not a resource hog and updates itself quickly even on a dial-up connection