Well, it turns out that I can't abandon Firefox completely on XP. While Maxthon browser is heaps better at numerous sites, I finally found one site where it wouldn't work properly - namely the American Express Connect site where one gets lots of handy cashbacks and other offers.
https://network.americanexpress.com/...n/default.html
At this site, it just doesn't display what it is supposed to display.
Regards,
Renato