packages meltdown

[Adam Hardy <adam.ant@cyberspaceroad.com>]

I'm using testing and debian has got itself in a bad way now.

I upgraded several packages 3 days ago and have been trying to sort it 
out since - I think the offending packages may be udev or libusb.

I also added a line for usbfs /proc/bus/usb to my fstab.

I subsequently lost my sound driver, my ability to open shell consoles 
in X, my CPU thermometer and various bits of gnome. My /dev/null is set 
to the wrong permissions on boot too.

I read some other people were having issues with udev here:

http://lists.debian.org/debian-user/2006/04/msg00631.html

so I decided to try to downgrade my udev to v0.79 (I can't deinstall it, 
gnome is dependent on it) but I can't find udev 0.79 anywhere to do that 
(either on any website or via package manager such as aptitude (no other 
versions available) or synaptic (the option is disabled for reasons I 
can't fathom)).

So I'm stuck. I can't figure out how to fix it and I'm wondering why I 
am using the testing distro after all. Perhaps I should downgrade my 
whole system to sarge? Or perhaps just reinstall testing?

I'd be v. grateful for any realistic advice at this point.

Thanks

Adam