For some reason PA makes an arbitrary decision to use Iron to open the support link (and others), which is one of the browser that happens to be installed on my system. My default browser is Opera, so any URL that is opened I want in Opera. Iron is not the default, for anything.
PA 10.1.2 on Windows 7 x64, Opera 12 is the default.
Again, please look at the topic pinned right at the top of this forum: https://portableapps.com/node/28593
Sometimes, the impossible can become possible, if you're awesome!