Comment 15 for bug 395403

Agreed, orbiting KDE cursors are a bit useless here. I have had to resort to my Nikon DSLR and just shoot frames until I finally got one that made sense. The fact that you got to X and the KDE logo is a good sign, of sorts. Try adding "single"
to the boot command line, leaving the delete of "quiet" and "splash" in place. This will take you to a shell prompt before
you would start loading wifi modules. If the hang happens anyway, at least X is not obscuring it. Take a picture.

Next you can walk your way through the startup. See http://help.ubuntu.com/commmunit/InitScriptList for details. In particular, follow the links at the bottom of the page to disable/deactivate a service at startup. The one you are interested in for Kubuntu is "kdm", the KDE+X startup found at /etc/rc2.d/S30kdm. You will get a text only multi-user when you disable that, giving you a better chance and finding where things are hanging. Remember what you change in this dir so you can restore it. You can disable other services to isolate where things are dying. Keep in mind that many of these startups work concurrently so console messages can be interleaved.

Does your system have a serial port? If so, try the usual "console=ttyS0,9600n8" line. ./Documentation/serial-console.txt in the kernel source tree explains in more detail. If you don't have access locally, you can view the doc at a Linux cross-reference site such as http://lxr.linux.no/linux+v2.6.30/Documentation/serial-console.txt. If you don't have a serial port, a USB console can be set up but that is a bit more complicated, unfortunately. Both of these require a second system running minicom or other VT100 emulator.

Let us know what you find.