Mine slid around a lot and I though maybe they had come out but they were okay. Did you double check that they were out? I rotated the shaft back and forth every so often to see if I could hear the gears clicking. I you can hear the gears clicking/moving then you should be okay.
From what I hear they should go back in to place with little effort. You may end up having to pull the boot off and reinstall the drive shaft. Hopefully not but that may be a necessity.
