I have this problem too,i can't solve it！Waiting for A to give advice or comments！thanks！
Hmmmm I don't get it. What's wrong with the extdts in this scenario? I've tried it myself (richfaces 3.3.3, seam and jboss 4.2.3) switching tabs seems worky and the content of both tables / tabs is shown.
have you tried putting an <a4j:region> (without any parameters) arround each of the extdts?