i had this problem before.
1.Check if your model is not away from the axis points.
2.DB doesn't support mesh deformation, you have to assign a group for every bone.
3.your model could be super small, or big, use AUTOCAM ON
4.5000 poly should not be a problem, db can still export them, they just run slower (depending on your machine)
5.i suggest using lower polycount models for games
6.UNCHECK the operate on selected joints only tab in milkshape
7.Make sure you'r not in animation mode.
Hope that helped
-----yosepp
if me in trouble() and 1=1 then print "but"