just crossing off one thing at a time
You just joined the forums in august so I didn't know if you started with 5b3 or upgraded.
(Let's put aside the fact that you think they worked for a bit, because even you're not really 100% sure.)
So let's just re-deploy the zimlets.
su zimbra
To see what you currently have available:
zmzimletctl listZimlets
Then browse to /opt/zimbra/zimlets (or -extras)
zmzimletctl deploy com_zimbra_something.zip
(this will enable it for the default COS only-you'll have to apply it to other COS's)