Fixing UV wrapping

I have a model with a UV wrapping issue; one polygon is apparently mapped to a single point (since it shows up in single colour in Mago's model editor), however, ingame it shows like a nasty red surface for some reason (WC3 probably can't handle stretching a texture that much). So, what program would I use to fix this issue (I couldn't find any UV wrapping tools in Mago's) and how would I go about finding which vertices to move on the UV wrap to fix it?

I think oinkerwinkle's tools have a UV mapping program built in

Vertex Modifier is the one you want, but with it the UV-mapping tool and the normal modelling tool are entirely seperate; there's nothing convenient like in Milkshape where you select shit in the main view and it carries that selection into the UV-mapper.