I encountered a few problems when entering combat when this mod was enabled. After disabling this mod they all worked as they should do. I always use the wow ace updater so I always have the latest versions.
ag_uf and pitbull
If i didn't target something before I entered combat my target and target of target would not be displayed.
bongos2 (only noticed this on my warrior)
when I changed stances the bar with my abilities appeared to lock preventing those abilities for that particular stance being displayed. However leaving cobat everything worked fine.
Bartender 3 did not have this problem.
I don't know if this is a problem with this mod or how the others are written etc. for the short period I used this mod I thought it was fantastic.