In PBwiki 2.0, I was editing a table that I had just created, and I added a background color to one of the cells. When I saved my page, the background color had not changed. I currently use Firefox.
When I checked out the page source, pbwiki had added a bgcolor attribute to the cell in question. I was able to fix the problem by changing it to a style attribute (namely, style="background-color:<color>"), but this hack really should not be necessary.</color>