unable to run synaptic

[Brian McKee]

>> >> > Yesterday I upgraded from 8.10 to 9.04, and today I am unable to run
>> >> > synaptic ! I get a window with the message:
>> >> > "failed to run /usr/sbin/synaptic  as root, unable to copy the users
>> >> > Xauthorization file"
>> OK. One more:
>> $ df
> kjetil at familien:~$ df
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/sda1             18544460  18141016         0 100% /

NoOp for the win!

See that first line?  Your root (base level, not user root) partition is full.
17 gig seems like a lot - you must have some stuff hanging around
there somewhere you can delete.  Post back if you need help finding
it.

Brian