I have been sent a rather complex protected XLSX spreadsheet with 1,053 formulae. They work fine. Three cells have a text string. When I open the XLSX file with OO, these three strings are twice as long as they should be (concatenated to themselves).
I had the author (who is using Excel) save and send me a copy with file type XLS, and OO does not have the problem with this file. So it appears to me that OO is has a glitch with XLSX file types. Is anyone interested in this problem? Unfortunately, I do not have a recent copy of Excel.