I found this out the hard way, only save low res models as in reduce you model to the lowest sub division before saving. Every single model I saved at higher resolutions developed errors. I posted quierries about this problem and had multiple people tell me about this idiosyncrasy. I was even told this was a problem by Pixologic when I asked about the corruptions. Unfortunately I don’t believe the documentation or any of the tutorials point this bug out. It’s been pretty devastating and has caused me endless headaches. Hopefully I have the problem under control now but I wound up with several corrupted models One is damaged beyond repair. Another I was able to repair and a third one I’m still trying to repair. It’s an amazing software but there are quirks and bugs and people need to be made aware of the problems. I’m sure most will be addressed in future releases but but a little forewarning can avoid lost hours or days of work. Got to say I’m more than a little nervous about importing the models and I’m very concerned how Lightwave will react to the higher polygon models. It should only affect the renders but rendering errors would be a disaster. One major recomendation I would make is if you can avoid subdividing past 600,000 I’d do so. All my problems came in at one million plus, give or take a few, polygons. The higher polygon models seem far less stable.
that never happens with me… the only thing that is good about saving in a lower subdivision then the tool is at highest is that the file size will get smaller 
Why would the file size be smaller? All of the information about the higher sub-d levels is still there right?
all the info is there Bill but I reckon zbrush somehow saves the info as a displacement map rather than a mesh. so saving the low poly + displacement (or whatever magic they use) = low file size as opposed to high poly count model alone = loads of mesh info = large file size.
not sure how they do it, don’t really care haha it works and it’s far better to save at lowest subd and save disk space on projects and live with regenerating the subd levels than risk losing valuable disk space and your hard work inmo.
I hadn’t even considered it that way.
Very interesting. Thanks.