Scott,
I'm not sure if Hippo is still around or not, but we have had plenty of experience with the computer modules. They all seem to go bad after a period of time. Your best bet is to replace the computer system with regular DPDT switches (that is of course if you can't get a hold of hippo). Also, Chris' suggestions are very good if your system is not pumping in the water. Either way, good luck. Oh yeah, if you do deal with hippo, make sure you do a COD or get the product up front!
Jerry Lembas
Fluid Concepts
www.fluidconcepts.net