I got a series of error messages and a number of objects that aoi was no longer able to read.
It were the very same objects I had copied to an empty document to edit them more easily. Luckily I had saved that scene so I was able to recover the last state of it all. But there seems to be some issue regarding copy/paste, elsewhere in the friendlyskies forum I read the such too.
Another issue: the Mac OS Aqua skin seems to break the preview render, it only shows a distorted, skewed pic. On returning to the default skin the problem is gone.
Figured you want to know.