Are you linking to a file on your device? (Using the “Attach File” menu option under “Edit”) If so, when you’re attaching that file, select “Embed the file in the document” in the file panel. This does increase the size of the OmniOutliner file, but it’s a bullet-proof method to keep those attached file links working.
Hmm, row links are a reference to the id attribute of a row. That id is generated at the creation of target row. I don’t know what would cause the ids to change. Would it be possible to send me a copy of this file so I can look at the xml? If so, please email it to omnioutliner@omnigroup.com and reference this ticket. Thanks!