@Andem ... it could easily be triggered from previous versions of IE. However, most people (still do) use I.E.8 rather than 6 or 7 or indeed 9 - so this to me was the main source of the problem - and I used a computer with I.E.8 loaded to see how it was affecting my site, and this version triggered the problem for me.
Facebook have had over 1 years notice about this 'problem' but have done 'nothing' about it, (not that I could research) because they have no idea what causes 'some' IE browsers to trigger the problem, and, not all sites experience it ...
The computer using I.E.8 that I used to 'see' the problem being trigged on my site was not a regularly updated version, (i.e. the latest versions of I.E.8) but it was certainly version 8. Later versions of 8 (with updates) seemed not to trigger the problem, although I did not hang around longer than two days to see if this problem was more widespread on my site.
Here is the problem from the users end ... What you see is the page being created normally as it loads, (including the adverts) then it automatically refreshes after the page loads to a 'new' page url with the ?fb_xd fragment, which is blank. But because you have 'seen' the page load, and 'seen' the information you are seeking come up before going to a blank page you automatically want to hit the browsers 'refresh' button thinking that it was a one off problem.
'A Perfect Storm' ... However this time you see the page load much quicker, the information you want is seen for a fraction of a second (because now it is in your browser's 'cache') before going to the blank ?fb_xd fragment page. This prompts your visitor to keep hitting refresh in annoyance because they can briefly 'see' the info they want, before it goes to the blank page.
Sometimes the page will refresh twice or three times (or more) on each hit of the refresh button ... hence literally one visitor, (who triggers the problem) in a matter of seconds, can make that page load (with any adverts and analytical tracking software on it) at least thirty or forty times before they give up, never to bother with your site again - A 'PERFECT STORM' OF A BUG!
Couple this with a popular site or page and 500 visitors to a page of 4000 unique visitors who trigger the problem (because not all of them do) can refresh that page upwards of 30,000 times! Doh! However although each refresh is calculated by your analytics program, (I think) adsense only counts ad impressions on fully loaded (refreshed) pages before going to the blank page, so the count is somewhat lower, although this is still in the thousands ...
Note: Rather than using a browser specific solution (I want to have the 'like' button used by everyone), I used the solution I suggested, which I checked works on all browsers creating the problem, while still allowing the 'like' button to be used.