Q. Dif dig sig - what does it mean? A. Different digital signature. Q. Why change the digital signature? A. It was an accident - which has been corrected in version 1.0.0.4. Since the first version I had decided to sign the application so that users would be able to identify an update from the SAME source they had come to trust. All certificates expire. When this one did I wrongly used a new one because it was easy/suggested, I should have renewed the existing one which was a bit harder. So 1004-dif-dig-sig WRONG! is version 1.0.0.4 with a different signature to 1.0.0.3 and earlier versions. 1004 RIGHT! is version 1.0.0.4 with the same signature as 1.0.0.3 and earlier Q. So What? A. DO NOT use the dif-dig-sig folders for new installations because future versions will not have the same signature and will thus not be seen as EXACTLY the same application when it comes to upgrade, making upgrade fail. 1004-dif-dig-sig -- used to be -- 1004 with wrong signature 1004 -- is now 1004 with right signature Q. Why is the wrong version still here under 1004-dif-dig-sig. Openness, transparency, honesty, for troubleshooting. I would much rather delete it, especially when I see it is getting downloaded. Indeed - this readme.txt file is aimed at those thinking this is the right version to use, if that is you my advice is to uninstall 1004-dif-dig-sig, obtain 1004 and install that, so that any future auto-upgrade will work should you accept the invitation.