I would be surprised if this was not known about, but the front page of Yahoo.com shows obvious rendering errors on Windows Vista Safari ToT (although not the released Safari 3.0.3). In the upper right of the page, there is a special area where the boxes will expand when the mouse pointer is hovered on top of them. In ToT on Windows, the boxes do not restyle correctly when hovered. Additionally, the tabs on the two main sections of the page ("Featured", "Entertainment", "Sports", "Life") do not change appearance correctly when they are clicked on, although the content changes appropriately.
I can attach screenshots, but the problem seems obvious enough to me that they should not be necessary.
Works for me with TOT on Mac. Maybe Windows-specific?
This was fixed by a recent checkin for VC compatibility.