A little help, please

[dalisprime]

Right, so as I mentioned in the other thread, I recently got rotf Swerve to serve me as my Sideswipe to partner up with Rally Sideswipe (as Sunstreaker). Problem is, the socket in Swerve's head is either too loose or I just can't pop his head on properly (which is rather unlikely as it looks to be sat properly) because the damn thing jumps off whenever I turn it. I guess it's mold degradation at work here (although to my knowledge this mold had only three versions, Swerve being the second). Anyway, to the point - does any of you have any suggestion on what to do to keep it from popping off all the time?

EDIT: I found out that this was a rather common problem. Can't seem to find a fix for it though...anyone?