debian repo for squeeze got problem?

[Umarzuki Mochlis <umarzuki@gmail.com>]

Just a few minutes ago, when I ran "aptitude update":

/usr/bin/lzma: Decoder error
Err http://debian.nctu.edu.tw squeeze/non-free Packages                         
  Sub-process /usr/bin/lzma returned an error code (1)
Fetched 202kB in 2min 48s (1,202B/s)                                            
W: GPG error: http://dl.google.com stable Release: The following signatures were invalid: NODATA 1 NODATA 2
W: GPG error: http://debian.nctu.edu.tw squeeze Release: The following signatures were invalid: NODATA 1 NODATA 2
W: GPG error: http://security.debian.org squeeze/updates Release: The following signatures were invalid: NODATA 1 NODATA 2

even the security repo?

-- 
Regards,

Umarzuki Mochlis
http://debmal.my