#cse & #search are your culprits, its a little hard to pinpoint the problem specifically. i noticed that #search has float:inherit... the key to IE6 is keeping your code clean
add/replace these two lines into your style sheet
#cse { padding:0px; }
#search { float:none; }
i cant figure out exactly why the padding causes a problem... but removing it seems to have fixed it.
-aPeg