Using Mac OSX 10.5.8, running Firefox 4.0.1, I am unable to switch to 32-bit mode; the "solution" offered at https://support.mozilla.com/en-US/questions/814007#answer-172365 does not work, as the "Open in 32-bit mode" option is not listed.
The site I referenced in my question is titled "How to open Firefox in 32-bit mode for Mac OS X 10.6?" There TonyE says, "To set Firefox to always run in 32 bit mode, open up Finder and go to the Applications folder. Control-click the Firefox app and click "Get Info", then select the "Open in 32-bit mode" option.
I am running Firefox 4.0.1, under Mac OS X 10.5.8, and when I do as TonyE suggested, Firefox does not show any option labeled "Open in 32-bit mode".
I am running OS X 10.5.8 instead of 10.6, but surely the Firefox "Get Info" box should look and work the same, even if I am using a slightly earlier version of the operating system. Why does this option not appear? How can I set Firefox to always run in 32 bit mode on my system?