Welcome. From a few hours looking for a solution why my site does not work in IE below version 10 In the last 10 - works great, just like in Chrome, Mozilla and every one - except the old IE.
The main suspect after reading this rubbish tips millions that adds Microsoft Word when you paste text. I never do but I asked people who writes on the website and found that, yes. They do it.
And now ... It is about 1200 entries. Manual removal of the code to see if it is a problem is slavery. Especially if it turns out that this is not a problem. There is a plug that will clear the filth of the Word in the entries?