AAAAhh, ok. Yeah you need specific plates to mount any binding to a Burton board. They are a pisser like that. I have a set laying around because of the one Burton board I own for the 4 days a year I might ride it.
i lost my burton plates also.. so now on my butron board i got it to work with the other set of base plate. but i coulden't exactly center my stance lol. it had to be a little wider set =[ still doesn't bother me, rides very well