Quote Originally Posted by vailr View Post
Unless I am mistaken, SATA ports 5&6 are under control of the JMicron controller chip (which I do not use and normally have disabled). I've already tried enabling the JMicron controller (in IDE mode) and seeing whether the SATA DVD-RW would boot from port 5, which didn't work either.

You are mistaken. JMicron is used for E-SATA.