I think I have found where the problem lies. On certain packages, just after "Downloading list of changes", as it's about to display the text it crashes.
Each of the following packages would cause a crash at that point:
kcontrol, kdebase-bin, kdebase-data, kdebase-kio-plugins, kdesktop, kfind, kicker, konqueror, kwin, libkonq4
These two and random others that I tested didn't:
If you click on one of the crash causing packages but you're Hiding Details or you're on the Description tab, it does not crash.
If you're on the Description tab, once the details have downloaded if you change back to the Changes tab you can view the changes list and it does not crash.
If you're on the Changes tab and it's started downloading a changelist and you switch to either Hide Details or Description before it's finished, it does not crash.
If you're on the Changes tab and go back to an item that you have safely downloaded the changelist for it earlier, it does not crash.