Good questions, Deanna - the interpretation of the Oviraptorid dinosaurs is a complicated one, but I'll try to be brief here. You're right, the name 'Oviraptor' translates as "egg theif"; the name was applied in the 1920's based on an assumption that the fossilised eggs found with the skeleton were in the process of being 'stolen', and the strange, toothless beak-like mouth thought to be an adaptation to breaking eggshells seemed to corroborate this. Other palaeontologists have since been a little critical of this interpretation, and newer discoveries of fossil skeletons of related dinosaurs like Citipati were found protecting their nests, and with evidence of their last meal - a lizard - as stomach contents. So, perhaps we've made a pre-emptive accusation and enshrined it in a name.
However, Oviraptorid dinosaurs had odd-looking skulls, particularly their beak-like mouths, and this makes it difficult to guess what they did eat. It's always hard to estimate the diet of an extinct animal, especially a toothless one. We can't rule out the possibility that Oviraptorids ate eggs at some point (as many carnivorous and omnivorous animals do), but the current interpretation is that the first Oviraptor that was described wasn't stealing eggs as the time of the fossil was preserved - it wasn't 'caught in the act', but this may not neccessarily mean it didn't do it at all for thier entire existence.
In any case, the name has stuck - no matter of innocence or guilt on stealing of eggs, Oviraptorid dinosaurs will remain with the accusational name of 'Egg thief', at least for now.