Like jmstacey there's people that achieved to managed it.
I'm with the same problem!
have installed CentOS 4 on a machine and now there is no compatibility.
I can't install on our server cause we have no license yet, and to buy it have to choose the OS version, and no centOS 4 on the list.
If you manage to work it, just tell me.
I'm willing to try too, my other option is to go to the datacenter and re install the machine