An error occurred when adding the reference

Hello,
when I try to add a reference from Bookends I obtain the following error message:
{Please activate again with a Bookends main window being Bookends’ front window."} doesn’t match the parameters {stringEN, stringFR, stringDE} for localizeString.

I use Italian SnowLeopard System.
Thank you

thank you for the bug report, we’ll fix this with the next maintenance release.

We have fixed this bug for the next release.