Update manager crashed last time I used it (although the updates seemed to happen OK.) Now it quits immediately if I try to run it, as does Synaptic. If I try apt-get from the command line, I get a Segmentation fault, e.g.
$ sudo apt-get autoclean
Reading package lists... Done
Segmentation faulty tree... 50%
How can I repair this?
Running 10.10 on a Dell XPS M1330 laptop.