False alarm. The thing about Duskblades is that they aren't designed to have a big repetoire of spells. The list for the rest of the levels certainly isn't large. But, it is large enough that you can make different Duskblades to have different feels.
The truth is, how many damaging zero level spells do you need? The Duskblade's primary schtick is that they can use spells to damage through their blade. Sure, they have a few other spells like spider climb, darkvision, etc. I suppose you could give the Duskblade something like light. But we're talking about zero level spells here.
If your alarm is going off, the game design flaw is that the Duskblade entry should say "You also know one additional 0-level spell for each point of intelligence bonus up to the maximum of four 0 level spells." The bolded part is what I added to the PHB II p. 19 description. It isn't really that big of an omission.