It can't boot up after install 10.5.5

[gmow]

Hi all,

I'm pretty new in Hacknitosh world, I installed iDeneb 10.5.5, system won't boot up by itself, you need to inset the iDened DVD into the DVD drive, then it can boot up. Am I missing something?

Intel D945GCLF2 Mini-ITX board, Atom 330 CPU, 2G ram, 250G HDD, DVD burner.

Many Thanks.
GMow