I'm not sure if this is actually the issue, in your case. However, even before discovering LinuxCE, I found out (the hard way) that the ATI drivers for Linux DO NOT support / permit DVD-playback thru the tv-out (svideo) port. I fought with my notebook, with an ATI Xpress 200m video card for several hours, before I came upon this info...
If the DVD truly does NOTHING, as you stated, I'm not sure if this is relevant, but wanted to mention it in case it is the same issue...
Hope to have helped!!