Painting - problems w/ popcorn

I have had zero luck painting over popcorn ceilings with a latex paint (roller) so I always roll with an oil paint. However, I have heard on this forum that this is not always necessary.
I recently was redoing a popcorn ceiling in a condo and tried patching it but I could not patch to a spot with solid adhesion to the gyproc so I eventually scraped it all off and primed, oiled and re-stippled.
How is it that you can roll over the popcorn with a latex (it always falls off when I do it). A ceiling expert in town told me the only answer was to spray or roll with an oil.
Any thoughts or suggestions?
PS: This forum is excellent.

It can be rolled, but its a very delicate procedure. It involves thinning the paint slightly, and only making one pass with the roller. Put it on fairly heavy, but not heavy enough to leave ropes or thick lines at the end of the roller. Never re-roll a spot you already did, or it will pull down the popcorn. After this first coat is dry, another can be applied a lot easier, and no fear of it coming down.

Or, just do one coat of flat oil with this method, and call it done.

As usually the area with this problem is in a finished home, I've never sprayed a problem popcorn before
I use the procedure PWG described
You really have to play it by ear, as he says it's a delicate procedure