Minimap sometimes 'smearing'

[medgno]

I have my minimap set to dock for indoor places such as caves and instances. However, since 3.1 it has started sometimes getting all smeary. I've attached a screenshot since it explains what's going on better than words.



I do have a decent number of other addons enabled, but as best I can tell none of them have anything to do with the way maps work, so I'm at a loss to figure out what the problem is.

I forgot to mention initially, but when I walk into the area that's messed up, the proper imagery loads.