Originally Posted by FBinNY

Getting closer, but not home. It seems we were mislead by your title description of an ovslized headtube, but let's move on.

CC 40 headsets come in two versions, press-in and integrated. Both use a drop in cartridge bearing, so there are two possibilities.

1- the cup is defective or damaged,
2- you're doing something wrong, ie. bearing upside down.

It's also possible that the parts are all OK, and it's simply a loose headset, or one that can't tighten because of a missing spacer, or other similar issue.

At this point, I'm out until you post a photo of the bearing sitting in the cup, so we can see for ourselves.