Facebook ?fb-xd_fragment hell

Facebook has been wreaking havoc with duplicate URLs on many sites, including ours. I get many requests like this:

http://sitename.com/index.php?fb_xd_fragment=
http://sitename.com/?fb_xd_fragment=
http://sitename.com/f17/harmonic-bal...fb_xd_fragment

The common fix for this, listed all over the place is listed on many sites, here's one example:

Facebook fb_xd_fragment Problem – .htaccess Solution | Paul O'Flaherty

Here's the fix listed on these sites:
#Redirect For Added FB Fragment
RewriteCond %{QUERY_STRING} ^fb_xd_fragment=.*$
RewriteRule ^(.*)$ http://yourdomain.com\/$1? [R=301,L]

In addition to the duplicate URLs, VB and Facebook's CSS seem to interfere with each other when the fb_xd_fragment is at the end of the URL. The VB page will load and render, and a second or two later the entire page goes blank (the forum's background image layer is elevated above all layers so that's all you see).

Now, if I implement that fix it, when the fb_xd_fragment rewriterule kicks in some browser continuously reload the page (hundreds of 301s in the logs). This does not happen when vbseo is turned off and removed from .htaccess. It doesn't happen all the time with all browsers, I can't make heads or tails of it.

The majority of the time it happens with IE versions 7 and lower, but I cannot duplicate it with IE7 myself. I do not have the option of turning off Facebook in our VB installation, nor can I ignore IE7 and earlier browsers (due to our audience they make up about 9% of our users).

I need help, either with .htaccess or VBSeo rewrite rules to fix this. We're seeing a drop in traffic due to these users abandoning the site.

Hello,

you can use the rewrite rule quoted in your post (put it right after "RewriteEngine on" line)