I don't think it's so much a browser issue, as I suspect (note the emphasis) that it's a PHP / your host issue.
Specifically, I can't help feeling it might have something to do with the way the browsers are being asked to behave in response to a header redirect and mod_rewrite / .htaccess rules etc. Somewhere in there it seems that a loop is being created that expires the browsers' ability to sensibly redirect the page, and it lets you know that.
This would also explain why it's happening on some installations and not others. After all, if you remove the browser as the culprit (as asv seems to have done) and you remove the installation of the package as the culprit (as is implied by the fact that only some are being affected by this, while many aren't) then all you are left with is something different about the affected users' hosts or some edit they've made (ie plugin / hack and so on) to their own installation.
I guess all we can do is ask those affected to be as descriptive of their host environments and any changes they've made and wait for a sensible pattern to emerge.