Pc wont boot with LG GSA-4120B

Have tried all slave\master connections everything, switching cables etc
when i start pc with dvd-rw connected… starts then powers off, only hdd and dvd-rw connected, worked before, cant understand why not now?
unplug dvd-rw hdd boots up fine…

Post more details like this:

PM: ATV V 120
PS: DVR-108
SM: GSA-4120
SS: DW1620

400w power supply
AMD 2,6 ghz
1gig ram
2 x 120gb 200gb hdd
winxp sp2
nvidia gforce 4
lg dvd-rw gsa-4120B

just will not boot whne i connect the dvd-rw anymore
also new porblem now, i disconnted the 200gb hdd, boots then cuts off when i reattached it again…do you think might be a power supply problem?