Has anypne else here had a problem of slow undos in Max 7? Everything else is fast, but the undo is taking ages. Its affecting a few of us here. In the UV editor it can be up to 20 seconds for an undo to complete.
Mine does that sometimes, but it seems to be only when I have DirectX shaders in the viewport. At least, that's the only thing I can find in common with the few files that get a slow undo - most of the time it's perfectly fine.
I have a theory that it might be something to do with Max creating "Shell materials" or backing up existing materials when using render-to-texture... but it's far more likely that it's just the viewport shader, as Steve says.