After trying to upgrade to the latest utorrent portable, it seems to me it is no longer portable. It is downloading a beta version which has autoupdate turned on by default and the option to disable updates is greyed out so you cannot shut off the updates. It ends up installing the updated version to c:\users\xxxxx\AppData\Roaming\utorrent\utorrent.exe . This, in my mind makes it no longer portable.
I'm not sure why the portable apps installer for utorrent is trying to download a beta release rather than one of the stable releases. The stable releases have the option to uncheck auto updates not greyed out and able to shut them off. The beta has it greyed out and attempts to auto update on first run installing a version to the roaming directory mentioned above.