Post your model, or a simplified version that causes the same error. And your step by step workflow. You're probably doing one thing in particular that's causing so much trouble.
that definitely does not sound like a max error, but something on your behalf. i assume you do not collapse your UV modifier down, then do stuff to the mesh and then your modifier doesnt apply anymore?
still doesnt sound like typical max behavious but more like user error to be hones. so yeah as eric said, can your post your mesh? maybe even save the step before and after it breaks. just as you have it in max