Being (partially) Dutch myself, I googled up some more-
Dutch courage (alcohol)
Dutch reckoning- an undetailed bill is presented; if questioned, the total goes up
Dutch comfort- "Thank goodness it wasn't worse."
Dutch concert- each musician plays a different tune
Dutch auction- the bid starts high, and is lowered until someone bids.
Apparently a lot of the derogatory ones stem back to a time when the Dutch and British were at war with each other.