OPML Editor suddenly opening URLs in only Firefox instead of default browser?

[Jack Baty]

This could be completely unrelated to my earlier thread here...

https://groups.google.com/d/topic/frontier-user/DIz_9mvW7ck/discussion

...but something else is going on that I don't understand. While debugging my earlier problem, I thought I'd try accessing my worldoutline on a different computer. I launched OPML Editor, selected Misc->Preferences, and the page opened in Firefox. Firefox is not my default browser, so that's odd. My issues in the earlier thread were that when choosing Misc->Preferences (or anything which opens a browser) nothing happened at all. I don't have Firefox installed on that machine, so perhaps something is forcing Firefox to open? This was not happening earlier this afternoon and only began perhaps 2 hours ago, right in the middle of trying to figure out how World Outline roots work. My fault?

[Jack Baty]

Update: Things are again working normally on my Air, but the iMac still doesn't open any URLs when asked by OPML Editor. I don't know what is different between the machines. Weird, no?