No VCDs for you!
Well, Imation got back to me, explaining that maybe I needed to update the firmware in my burner (hah) or maybe the discs were just incompatible and that I should return them. No chance there; I don't have the receipt or even the label indicating the part number. So I gave them to Ari to play with.
I'm getting a Philips 50 pack for about $6 shipping after rebate, and I hope those work better. Otherwise I'm just going to go onto eBay and get some Taiyo Yudens in bulk.
I got some working CD-Rs from Rick, and I re-burned the SVCDs and VCDs. Brought them home. Still "No Disc". Does anyone know how to make the GoVideo DVR4000 play those damn things like the manual and box say it will?