Does the 64 bit client still require you to install the ia32libs in order to work ? I guess it's been a little bit since I've done a new one. Before, you needed to do that in order to run the work units, which are 32 bit. I believe some projects may now have native 64 bit code but some not.
Also, an editing idea, include a link to the ubuntu download page instead of directly to the .iso files for the current versions.