You can chek if everything is snapped, by
opening the level as textfile.

There you can watch the vertex-coordinates.

If snapped, they should have nice even values.
Else they have some floatingpoint values.
(causing the compiler to have a hard time creating
the BSP)

Some small recent games of mine:
Griefer 4k http://damocles11.byethost9.com/griefer4k.html
Kobold 4k http://damocles11.byethost9.com/kobold.html
Cave 4k http://damocles11.byethost9.com/cave4k.html