Been mulling it over, and haven't been able ot come up with anything definitive.
Below the text size option for IE under the view options, there is something called 'encoding'.
I have mine set to "Western European (ISO)" at the moment.
Setting it to "Western European (Windows)" has some minor effect, but nothing truly outstanding as to be obvious at this point.
Have you installed any new fonts lately?
I'm currently using Windows default Times New Roman.
Changing fonts, even to one similar to TNR, can make things display oddly.
There is a setting to tell the browser to ignore webpage formatting, but at the moment can't recall where it's stuck in Windows.
I set the web fonts to Arial. Setting it back to Times New Roman and voila, problem solved.
Just for fun set your web fonts to Arial and look back over this thread, only then will you see what I meant in post#10, and basically everyone must have thought I was on something as only in Arial does it change the fonts like that, so post#10 looks like 2 duplicate settings, but in Arial you see what I was trying to say.