"Update" is probably most profitable command in the whole Publisher - the single option that may overwaight all disadvantages of IP (except losing data of course).
On that particular project the Update was used quite often. If the IP13 Update command is causing the fail-to-load problem than only fact worth to note - not every case of Update usage resulted in inability to open the saved file (btw, inability to open happened several times*).
We should have stopped developing IPB just after first inability (data loss) but first several problems were write off to "something wrong".
It was suddenly clarified that there is already Publisher 2014 available (Autodesk called it 2013R1).
Alas! File that failed to be opened in 2013 is failed to be opened in 2013R1 as well.
Critical bug isn't it?