Segmentation fault when stating aptitude

[Jacques Dery <deryj@inforco.com>]

Last time I ran Udpate Manager (Desktop --> Administration --> Update
Manager), when I clicked the Check button (Check the channel for new
update), the download stopped in the middle.

Since then, when I launch the application, I get a segmentation fault
error.

I tried running apt-get update and aptitude from the commandline with 
the same result. I looked at the man page. I tried a few commands 
without result. I am weary going further because I am playing with root 
and risk doing more damage on the system.

PLease help
Jacques