GlenB,

My thoughts...not to worry. Most likely everything is fine. This time of year you wouldn't expect to see any fish come to the feed, especially little ones newly stocked. I would expect to see some FH around the edges of the water, but even the absense of that wouldn't be cause for concern.
When spring gets here and you start feeding again if you don't see any activity after a couple of weeks...then get concerned. The few dead ones you are seeing are probably from the trama of the initial stocking.