Wow Yahoo! was release they new service, and amazing this service not supported when run on Internet Explorer 7 beta 2 (as I know), when I try to post question, sub menu on category dissappear. look my screen shoot.
update
Then I ask Yahoo! Answer and my question was answerwred by Yahoo! Answer team 
IE 7 Beta 2, as beta software, is not yet bug-free. It fails to display certain aspects of Answers properly. The current production version of IE (IE 6, Windows XP Service Pack 2) does render Answers properly, as do Mozilla Firefox 1.5 and other browsers. By the way, Solidus, the Windows XP operating system doesn’t play a role in this problem.
You can check their answer here
Ah, nevermind…
Nanti IE yang akan datang akan tambah keren kok dibanding FF..
*Ngarep*
Kalau aku sih tetap pake maxthon aja.
yahoo mail beta juga gag jalan di IE 7.. so?
masih belom pngen mencoba
#ardho: IE sucks????
yah untuk sementara ini aku masih cinta ama Firefox dan Opera.
maniak Yahooo!!!!!
Y! answer pertanyaanya pakai bhs eng yah?
coba – coba deh ane
yahoo mailku kok type betanya hilang n cuman type classic aja…
gmn cara mengembalikan ke type beta lg?
internet explorerku versi 6, mohon masukan n sarannya, trims…