See http://new.nynjtc.net/action/parks-display-whatisit-iefor an explaination of the bad effects noticed by GW.
All of the parks need to be looked at. All the rich text fields had it in the park I looked at and fixed, Abram Hewitt.
A little more info on pasting in general. If you use Paste from Word you seem to always get the leading trash and have to delete it. If you Paste as Plain Text (icon just left of W with a T) you don't have those problems but you lose most other markup. For simple text this may be your best choice.
So part of action item is to document how to deal with Word files. My solution is to not use Word. I enter text direct into web page or paste from other sources like notepad, PDFs, WordPerfect (which has its own problems but not as severe as Word).