visual/html editor does not save changes.

When I try to add code to the html editor it is lost when I switch to visual view.
For example I tried to add: <br style=”clear:both;” />
but it will not stay.
I added it inside div’s
<div> <br style=”clear:both;” /> </div> but it was cleared again when I switched to visual view, the div’s where left though.
It is the same for <p> tags…
This is making wordpress unusable to create even simple pages.