I totally agree with this. I've got models that are from Pro/ENGINEER with bloody relative accuracy and if I'm ever unfortunate enough to have to use them in manufacturing, I have lots of problems. Sometimes the manufacturing module will refuse to do anything with them, will not run simulations, etc. Other times, particularly with complex surfaces, I will get the "plunge to infinity" error when the cutter passes over a particularly bad surface-to-surface interface. And sometimes, just to make things even more interesting, toolpaths will work, but then if I change any of the stepover parameters or anything that changes the space between passes, it will fail. It won't tell me why it failed, but from experience the first thing I always suspect is the model is in relative accuracy.
The trouble is, it's a simple thing to set up a mapkey that I press and it changes the accuracy to an absolute value. I have this and it's great, but in some cases, like the aforementioned complex curvature parts, this can cause the model to fail. It's particularly nasty with models that have complex intersecting rounds, because the accuracy improvement results in a new topographical arrangement and number of surfaces.
Additionally, try to make sure all the models in your manufacturing assembly have the same accuracy, and your manufacturing assembly itself is the same as the models.
If you're using start parts that have been around since the old days, replace them with new models that have the proper accuracy settings. That way, at least with newly created parts, you won't have these troubles.
