No, that's not normal. The only contained DLL, USBCALLS.DLL, should be unlocked, so you should be able to install it over an older version. If you can reproduce that on another system, open a ticket at Arca Noae's Bug Tracker. BTW: It works here, provided that we are talking about the same USB package: USB-12.13.exe, but prior versions worked for me as well. I've installed them all, so the last update was probably from 12.12 to 12.13.