Hi Jedrek, that hotfix is only applicable to pre-SP2 versions of Server 2003.
The second error that you receive sounds like you are trying to install the pre-SP1 version of the Compute Cluster Pack on your machine? You need to use the CCP SP1 disc to install in this case; which you should have received when you ordered your SP2 slipstreamed version of CCE.
The naming is a little confusing, so let me write them out:
Windows Compute Cluster Server 2003(the original RTM version) included
Windows Server 2003 Compute Cluster Edition (x64, so it has 2003 SP1 built-in)
Compute Cluster Pack <-- This one will only install on original Server 2003 x64 builds
then the first service pack of the package was called:
Windows Compute Cluster Server 2003 w/ Service Pack 1, and included
Server 2003 Compute Cluster Edition w/ SP2
Compute Cluster Pack w/ SP1 <-- This one can install on any Server 2003 x64 install with or without Server SP2 applied