the dreaded Chinese Puzzle

[Erik Addy]

I too had a CV joint come apart while putting a new boot on last summer.
 It was the inner joint on one of the front shafts.  I put it back
together (after plenty of profanity), and it would move.  So, I figured
I must have done it right because otherwise it would lock, right? 
Anyway, ever since, I've had some humming in my driveline, and wondered
if it could be related (I did some other stuff at the same time, so I'm
not sure).  Any suggestions?  Could I have put it together wrong, yet
have it still be able to flex?

Thanks,
Erik