lenny testing: ugly display

Question

I have upgraded my Debian Lenny install from "stable" to "testing", because I wanted/needed the higher versions of mono and monodevelop to continue work on a project that was initially start under a Fedora system and depends on some of the libraries.

The upgrade itself was a mission, mostly due to the fact that the boot loader sits on a different disk, which grub 2.0 doesn't see during the upgrade. But, after some fiddling, I did get there and I now have a working Lenny "testing" system.

However, the display on the monitor is somewhat less than satisfactory. All the colours have gone to extremes. Where previously shaded items where clearly visible, they are now barely distinguishable from the white background. And somehow the colours appear off, like a TV where the colour saturation has been turned up to overdrive.

Edit: lspci identifies the graphis as this: VGA compatible controller: ATI Technologies Inc RV280 [Radeon 9200 PRO]

According to the Xorg.0.log, the following modules are loaded: (II) LoadModule: "dbe" (II) LoadModule: "extmod" (II) LoadModule: "glx" (II) LoadModule: "record" (II) LoadModule: "dri" (II) LoadModule: "dri2" (II) LoadModule: "ati" (II) LoadModule: "radeon" (II) LoadModule: "vesa" (II) LoadModule: "fbdev" (II) LoadModule: "fbdevhw" (II) LoadModule: "fb" (II) LoadModule: "ramdac" (II) LoadModule: "shadow" (II) LoadModule: "evdev"

Unfortunately I don't really know which modules were loaded before the upgrade, sorry.

However, under Lenny "stable", this was all working perfectly fine, using either Gnome or KDE. Now KDE has become basically unusable.

Has anybody had a similar problem? Any ideas would be much appreciated.