recursive "already installed" message
Perhaps it is a known bug, but when I try to install Mustang build 56 I get a message "This software has already been installed on your computer. Would you like to reinstall it?". This message is correct, but when I click Yes, it does some work and then asks the same question again. Clicking Yes again brings up the same question dialog. And so forth.
I think the installer used to instruct to deinstall first. Installing over a previous version is much nicer, if it would work...