booting from cd

I have an epox 8KRA2+ mobo but I have a problem with it detecting my DVD
drives especially when it's warmed up. if cold then it can usually boot
from DVD if set in bios but normally I have to remove a hard-drive so it
cant boot and then connect the drive up again while it's still switched on !
is there any way so slowing down the mobo so it can find the drives.
at the moment I can either see one of the drives (but only one at a time) or
none of them. I've tried switching the power cables and even checking the
IDE cable connections but without success.
any ideas would be gratefully welcomed. my DVD writer wont play my kids
QuickTime cd's and of course the DVD drive wont record anything (I do a lot
of backups of downloads so I don't have to wait a second time).

Help ppl.

Robin