Frank,
Another strange observation I've discovered about this is that if I edit a product and place FCK Editor in "Basic Text Box" mode and proceed to make changes to the html then update the product it does NOT apply the changes to the product.
In one case I removed quotes, updated the product, then viewed in a different browser and the quote was still there. When I switch to "Rich Text Editor" mode and follow the same process then the updates apply.
This may help you pinpoint the issue.
Thanks,
Bacus