[CentOS] Kickstart issue: 'dialog' doesn't work in %post, CentOS 5.5

From: Zhang Huangbin <zhbmaillistonly at gmail.com>
> I use 'chvt 3' in ks file to switch to 3rd tty, but it stays in 1th tty (installation console).
> Swith to 2nd tty with 'Ctrl+Alt+F2', run 'ps' command, i can see dialog process is 
> running.

I just tested my kickstart with 5.5 and it does fail too now, while it was working with 5.4.
The pre ks process was running, but on no vt...
I ran my script by hand from vt2, then killed the old stuck one and anaconda switched 
to vt1 and displayed: "Can't ask a question from command line mode!"...

I also do:
  chvt 3
  /tmp/misc/ks_pre.sh | tee /tmp/ks_pre.log 2>&1
  chvt 1

JD