corrupted styles? I do not know that I have seen any of those...what happens to them, or what do they stop doing?
They look like the attached image. They can't be edited, only deleted.
It's related to the MOO errors. There are at least a couple of ways to create the problem; the simplest is to create styles in a parent/child relationship, and then try to move styles between drawings. (I know some who have basically decided to avoid using child styles, as the "brute force" way to avoid this problem.)
I'm hitting them right now because I'm trying to avoid creating all my styles from scratch, and am moving styles between drawings. I also have some styles that I had to go back to C3D 2007 in order to create, because they use Expressions in Reference Text, and I have been dragging those into my C3D 2009 template.
But like I said, I think I'm finally getting a good handle on how to deal with them. Sometimes, though, a couple of styles in a tree of related styles will end up like this and I can't get them cleaned up. In those cases, I simply have to delete the bad ones, and recreate them from scratch.
The good news is that this problem doesn't crop up much once all the styles are set.