Woodhead (Molex) is the specialty player in wet receptacles/ kitchen washdown environments.http://www.molex.com/woodhead
This situation may require abandonment of GFCI receptacles -- to be replaced by GFI circuit breakers and Woodhead washdown cord caps.
Given enough time, you can be assured that filth has invaded the inner workings of ANY GFCI receptacle on the market. They are not designed for sloppy soap/ water jets.
I'd be VERY surprised if the new equipment is the source of the trip.
BTW, there's no way the new unit has a bonding between the neutral and the grounding conductor, is there?