For Firefox 1.5, the "Samba Web Administration Tool" comes _over_ the horizontal line, not under as it should. This means that it gets partially overlapped by the Samba logo.
Can't reproduce it. Can you attatch a screenshot? Also, are your font settings different than FF defaults? And do you see the same behavior on samba.org, or only with SWAT?
Can't reproduce it any more -- looks like a Firefox upgrade fixed it.