http://www.quirksmode.org/bugreports/archives/safari/index.html "Attempting to get a text input field to expand to fill the browser in a nested table (table-layout: fixed) will cause the input field to overflow its surrounding table cell. Occurs with select boxes as well. Test page http://mattwright.com/safari/inputoverflow.html Workaround is not included Reported by: Matt Wright."
I can confirm that this bug is still valid on 24 june 2006 :)
Changing component.
The test case works now (matches Firefox 2.0.0.1 rendering). Probably fixed by one of Mitz's recent table layout fixes. Tested with a locally-built debug build of WebKit r19202 with Safari 2.0.4 (419.3) on Mac OS X 10.4.8 (8L127). I posted a comment to the quirksmode bugreport, but it's been filtered until the author clears it.