With i.e. limited disk space, it can be desirable to swap to a file. The installer refuses to install without a configured swap partition. In my case, I wanted to swap on a file on a DOS partition. I think that problem was not in redhat-5.2. So a workaround might be to install 5.2 first, and then upgrade to 6.0.
In order to install with no swap partition, you will need to install in expert mode. Entering "expert" at the boot prompt will allow you to do this.