I applied a STL check to the high poly,and then when there was nothing on the receiver that was red or selected I tried it on the high poly and still nothing. The only thing other I can think of that I did was I triangulated it when I exported as obj somewhere down the line but that was a while back.. its in quads still…
It sounds like your lowpoly model has bad topology. T-shapes: http://www.digitaltutors.com/forum/showthread.php?31708-Mudbox-Import-Issues-What-is-exact-a-T-Shape In 3ds max, add a STL Check modifier, and fix what it shows you.…