DarkBASIC Professional's engine has some problem with using DirectX's Hardware Multisampling.
What this problem is, i'm unsure - and it has been talked about before with the problem baffling the TGC programmers Mike and Lee.
Even more baffling to this mystery is the fact that using nVidia or ATi cards and turning on the cards FSAA abilities they will work perfectly with DBP - yet the equivilant DirectX version doesn't.
will keep trying to find out, however personally my thought on this leads to how the Shader system is implimented as earlier builds of Tomb Raider Angel of Darkness & Half-Life2 have both suffered from this affliction (both of which using the DirectX9 APi and are based on Dx8.1 Shader Engines)
problem probably lies with the DirectX APi using shaders itself, or atleast the readiness implimentation.
But no one can find a problem with either, just a correlation.