Change the URL might not fix the problem, as facebook can still track you down by user agent, and even the http://www.facebook.com/home.php will recognize you eventually.

The solution to the problem(once and for all) is to change the user agent of your MicroB.

Procedure to change user agent:
1) In the address bar of MicroB, type about:config
2) you'll be prompted a warning of warrant void something, do not proceed if you're afraid
3) in the filter, type user
4) you can find "general.useragent.vendor" at the bottom, select it and press enter
5) change the user agent in the dialog box to something else like "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US)" (without quotes)

Now browse ANY site without having to worry about switching to mobile page.

Hope this help.