I just thought I would mention that I have the Cadence IC tool set working nicely on Ubuntu 7.10

Assura 3.17 works great, which is a tool many have had trouble with in the past.

Additionally, the Virtuoso XL offscreen display problems I have had with Fedora are gone.  Although I like Fedora, I had hardware reasons for the switch.
IC5141, Virtuoso Schematic, ADE, Wavescan, Waveform Calculator all work fine. I have been using the install for about two weeks to run circuit design, simulation and layout with two different PDKs.  
Ubuntu keeps it's install compact (1 CD), so it does not install every library Cadence requires.  After getting Ubuntu installed and stable I went online with the Synaptic Package Manager and clicked the following additional packages:

libc6-dev
g++
csh
ksh

Ksh was the key to getting Assura DRC running.

I hope this is helpful for anyone needing to use Ubuntu with Cadence.

-Makelo