halt at: Configuring packages ...

[jack <ifup@yifan.net>]

hi,

I did a routine upgrading. OK with apt-get update, but apt-get 
dist-upgrade caused seg faults when it's trying to setup 
xserver-mach64.  Then, after exit X, I did dist-upgrade again.  it told
me to do "dpkg --configure -a" first.  I did.  then apt-get upgrade went
not too far and stopped for certain error.  ( sorry, I did not write down
what error it was )  Now, I am not able to to get apt-get upgrade( or
dist-upgrade ) to work at all.  It just halt at stage: Configuring
packages ...       

any idea?  it shows there are 43 packages not upgraded yet. ( whole story
happened last night and I am using potato )

tia,

jack