Based on what I could read around, adCenter does not offer exact negative match - is that right?
I don't want "shoes" to trigger my ad, but "black shoes" I do.
What I see is that "shoes" as a negative keyword will simply stop anything that has "shoes" in it.
Almost a month without a post?! Is it because folks are busy with Bing gaining in search share or because adCenter went downhill? ;)