The devices /dev/sg0 through /dev/sg7 are missing in Redhat v5.2. As a result of these missing devices cdaa2wav is non-functional under Redhat v5.2
The standard names are /dev/sg[a-g], and those devices do exist. The bug is in cdaa2wav for not looking for /dev/sg[a-g] as well as /dev/sg[0-7].