libgdk-x11 symbol lookup error

[Don <dulist@noark.net>]

Back in March, I suddenly starting having problems with the startup of 
certain programs I regularly use (date around March 14).  The programs I 
believe all use GTK and the error message is the same.  Some of the 
applications are: iceape, synaptic, and geany.

Here are the results when I try running them from the command line:

don@kali:~$ sudo synaptic
synaptic: symbol lookup error: /usr/lib/libgdk-x11-2.0.so.0: undefined
symbol: g_malloc_n
don@kali:~$ iceape
/usr/lib/iceape/iceape-bin: symbol lookup error:
/usr/lib/libgdk-x11-2.0.so.0: undefined symbol: g_malloc_n
don@kali:~$ geany
geany: symbol lookup error: /usr/lib/libgdk-x11-2.0.so.0: undefined
symbol: g_malloc_n
don@kali:~$

When looking for /usr/lib/libgdk-x11-2.0.so.0, I find a link to:
libgdk-x11-2.0.so.0.2000.0, a size 609700 file which is present in the 
/usr/lib directory.

Using 2.6.32-3-686 #1 SMP with squeeze/sid.  I do the apt-get update and 
upgrade periodically.

Never a problem like this previous to mid-March or so (cannot pinpoint 
date as I was out of circulation in hospital for a week late March and 
just getting around to finding a solution).

Any help appreciated -- knowledgeable enough to be dangerous, so even 
though I'm not a newbie, don't assume I'm an expert.  I may have done 
some dumb thing to cause this as I don't see anyone else having this 
problem.  Let me know what other information is needed.

Regards,
Don