99% percent of the time that error you are getting is resolution related. Either out of graphical limits, refresh not matching.....something.
UF is definitely more forgiving that Titanium but honestly, you would have figured with this many expansions they would had gotten that handled by now
I still get graphic anomalies from time to time if I log in and out a few times on my client. Either the client gets mega laggy or I get some crazy vertex thing going on that makes the NPC's look like they are on an acid trip.