[SoUlFaThEr]

advice on vertex manipulation:

do manip on one block tilly er done.....the do a "check for problems". if you dont get a "invalid structure" message........then yer good to go. do the nest block manips.

also....if you make complicated things.....with slants in 2 directions and other stuff.......and have each vertex on the grid........and then ROTATE this thing to anything but 0,90,180,270.then you may end up with errors too even tho it was done right....in this case....dont rotate the object.

repeat the process.

coplaner plane is having 2 vertex on the same line........just simply pull one of those vertex's onto the other on in its corner.......and say YES to the popup asking you to merge vertexs.........