I am by far not a expert. It sounds like it is a problem I had before.
The only way that I get my clean listings is to copy from notepad. MS products leave a lot of junk behind that you can see switching to html mode.
This is a problem that I have run into using other submitting software also.
Also if you are importing from eBay tn working on them I copy the text to notepad then switch to html mode and clear everything.
It's is unreal what hides behind the scenes.