Built up2date-2.1.7-0.6.x from SRPMs and installed. The package loads and registers successfully, but when running the initial dialogs, the following system error occurs: There was a fatal error communicating with the server. The message was: Invalid Architecture and OS release combination. Note: I am running RH 6.0 with latest applicable updates, and linux kernel 2.4.0, compiled from sources (not RPM) on a system with AMD-K6(tm) 3D+ Processor (450 MHz), 256 MB RAM.
Red Hat Network / the new Update Agent are not supported by Red Hat Linux earlier than 6.2.