I tried to install Houdini on a kubuntu system:
Linux mjoelnir 2.6.35-22-generic #35-Ubuntu SMP Sat Oct 16 20:36:48 UTC 2010 i686 GNU/Linux
I used houdini-11.0.547-linux_i686_gcc3.4

During installation I got this error:
ERROR: Problem installing Houdini desktop items

I can start the program, but all buttons are white
Is there a problem with KDE?
I turned off all desktop effects, but this didn't help.

Ok, I solved it.
I installed this one:
houdini-11.0.547-linux_i686_gcc4.4

Though I'm not sure if it's because of the new install or just because I rebootet the machine between the installs.