The question is, why on earth was that folder created from an addon manager update?
It shouldn't have. I start to suspect there's a bug in the installer program (not the one we wrote, the one we use to create the installer, which is Innosetup), which seem to ignore a command to install/update certain files only if another file exists.
With the previous version of the installer, we used to check the folder, but this caused some problems if an user had an empty folder so, in order to FIX this (go figure), we changed to check if actual *files* from XPOI (or any other module that might need to be updated) were installed IN that folder but, looking from reports, and assuming all these users never had XPOI installer before, I can only conclude it's a bug of the installer program, which doesn't report correctly if a file exists or not IN a folder, while it USED to work to check for just the folder itself...
I guess we'll go back to the previous check of just the folder, as it used to be.