Dual-monitor with Radeon & XFree86 4.3.0

I HDinstalled Knoppix with a Radeon 7500 and 2 monitors (xinerama not clones). Knoppix with XFree86 version 4.2.1.1 worked fine in the dual-monitor config (with appropriate changes to the XF86Config-4 file). When Knoppix upgraded to XFree86 version 4.3.0, using the same XF86Config-4 file now no longer detects the second monitor. I wrote a bug to the XFree86.org people but the "bugzilla big kahuna" simply flamed me saying it must be my configuration problem. Are there any HDinstalled Radeon users out there running a dual-monitor configuration with XFree86 version 4.3.0? If so what's the secret to getting the dual-monitor mode working again.

Any help would be appreciated,

- Nat Martino