I also had the Export/Import problem with complex text. I was using MS Offce (2013) and LibreOffice and both were unable to save in .CSV format that was acceptable to TuneBrowser.
However I was able bypass this limitation using a text editor:
(1) Export the data from TuneBrowser (.CSV format)
(2) Open the .CSV file in a text editor (I used Notepad++)
(3) Change the data requiring correction and save the file.
(4) Import the data into TuneBrowser. It works 🙂
The export function of TuneBrowser is extremely useful for locating data and fixing any errors, I use it to cross check all my metadata.