@Quad:

[mesh tester my model]
All meshes: 4
Closed: 1
Opened: 3

[mesh tester guard.mdl]
All meshes: 20
Closed: 0
Opened: 20

About the vertices, maybe that could be the reason? my model does have significantly more vertices, since it was highpoly before... do you know of a way to reduce vertex count? also, am surprised that the difference is that great

@chris_oat: ive tried both textured and untextured, same result