Inner CV-Joint Pops Out

I'm wondering if anyone has ever had an inner CV-joint work its way out of socket before. I replaced the CV-Joint, but it still seems to work its way out.
I do notice vibration from that general area on acceleration between 1800 to 2100 rpms in 5th. when the joint is inserted to the transmission i do notice wall to wall play. I don't see anything about any type of bushing to replace in the manual, but i'm sure there has to be. It seems as if the ring clip doesn't make it to the groove to release and lock, but i just don't know. Can anyone help ???

You should feel a slight "click" when you insert the inner cv.... you should not be able to seperate it by hand once inserted. Sounds like your not installing the clip correctly. Are you using the old one or a new one? I would get a new clip if your whole axle assembly wasn't new.