Can't store OmniOutliner files

[ahoward]

I'm running r4003. When I try to store a copy of an OmniOutliner file (.oo3), nothing happens. Neither drag and drop nor the new item button work. Tried it on Trevor's machine, running Sync Preview 3.6 Stable and it would load one file, but not another and the file that it did load became corrupted. It will save links to the same file. I added another file with a number in the extension and that worked fine, so that's not it. I can't make heads or tails of it.