Hi everyone,
Just a quick question on something that I know has to be really simple..... but I don't know how to do it. Maybe someone can help me figure it out.
I took 3 hi res balls from my primitives, and the hi res square, too.
I set up the balls in the air, then hung the square above them. I did it so that the balls are under the very edges of the square, so I can run a cloth simulation on the square. I want it to drape over the balls, hanging down from it's edge. I'm planning on making it look like a cape or a cloak. But when I run the simulation, the 1st few frames look fine, but by about frame 5, the square slides off the balls and falls all the way to the floor by frame 30.
My question is how can I make the square "stick" to the balls so when I run a cloth simulation on it, it hangs, but doesn't slide off them?
Any help would be really appreciated.

Thanks -

in cloth room select "edit constrained group" and add a few points where you want it to stick.
Like on a blouse you would add point around the neck to keep it from falling off

I just tried that and it didn't work; I tried to add the points to the balls, but it wouldn't let me do that. It would only allow me to add them to the square. So I did that, right on the parts that would contact the balls as it drapes. When I ran the simulation, the square passed right through the balls - like they weren't even there. Not sure what I did wrong....

I just make quick test on scene you describe.
for some reason hi-res ball does not work, but regular ball does.
constrained group works for all figures I have used in past

You might need to check the extra collision detection options to ensure poser gets a hit. You can also increase the friction value to absurd high values . 

try looking at the scene in wireframe mode , that can sometimes give you a hint to whats happening .

There must be peculiaritry of hi-res ball.
I use ball, box, and sphere made in 3dsmax.  They all work like expected

Try lowpoly's suggestion, except with choreographed group instead of contrained group.  That will force the edge of the square to stay exactly where it's placed.