Same here, a desktop with Radeon graphics driving a Philips 190B LCD (on the VGA cable, not DVI).

Interestingly, if I restart the PC and select an older kernel from before I upgraded to Gutsy (2.6.20-16-generic) then it's okay.  I'm starting with the following kernel options in both cases:
vga=794 quiet splash

Here's the outputs I could get, I don't think I've installed fbset (it wasn't installed, and after aptitude install fbset, it still complains about a missing /dev/fb0 device file, so I've missed something there, sorry):


$ sudo ddcprobe
[sudo] password for mike:
vbe: VESA 2.0 detected.
oem: ATI RADEON 9200
memory: 131072kb
mode: 800x600x16
mode: 1024x768x16
mode: 320x200x32k
mode: 320x200x64k
mode: 320x200x16m
mode: 1600x1200x256
mode: 640x400x256
mode: 640x480x256
mode: 640x480x32k
mode: 640x480x64k
mode: 640x480x16m
mode: 1600x1200x32k
mode: 800x600x256
mode: 800x600x32k
mode: 800x600x64k
mode: 800x600x16m
mode: 1600x1200x64k
mode: 1024x768x256
mode: 1024x768x32k
mode: 1024x768x64k
mode: 1024x768x16m
mode: 1280x1024x256
mode: 1280x1024x32k
mode: 1280x1024x64k
mode: 1280x1024x16m
mode: 132x25 (text)
mode: 132x43 (text)
edid:
edid: 1 3
id: 0830
eisa: PHL0830
serial: 00035d4f
manufacture: 36 2005
input: separate sync, composite sync, sync on green, analog signal.
screensize: 38 30
gamma: 2.200000
dpms: RGB, active off, no suspend, no standby
timing: 720x400@70 Hz (VGA 640x400, IBM)
timing: 720x400@88 Hz (XGA2)
timing: 640x480@60 Hz (VGA)
timing: 640x480@67 Hz (Mac II, Apple)
timing: 640x480@72 Hz (VESA)
timing: 640x480@75 Hz (VESA)
timing: 800x600@60 Hz (VESA)
timing: 800x600@72 Hz (VESA)
timing: 800x600@75 Hz (VESA)
timing: 832x624@75 Hz (Mac II)
timing: 1024x768@87 Hz Interlaced (8514A)
timing: 1024x768@70 Hz (VESA)
timing: 1024x768@75 Hz (VESA)
timing: 1280x1024@75 (VESA)
ctiming: 1280x1024@60
dtiming: 1280x1024@70
monitorserial:  BZ  220495
monitorname: Philips 190B
monitorrange: 30-83, 56-76
$ sudo lspci
00:00.0 Host bridge: VIA Technologies, Inc. VT8366/A/7 [Apollo KT266/A/333]
00:01.0 PCI bridge: VIA Technologies, Inc. VT8366/A/7 [Apollo KT266/A/333 AGP]
00:0a.0 FireWire (IEEE 1394): VIA Technologies, Inc. IEEE 1394 Host Controller (rev 46)
00:0b.0 Ethernet controller: D-Link System Inc RTL8139 Ethernet (rev 10)
00:0c.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 08)
00:0c.1 Input device controller: Creative Labs SB Live! Game Port (rev 08)
00:11.0 ISA bridge: VIA Technologies, Inc. VT8233A ISA Bridge
00:11.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
00:11.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 23)
00:11.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 23)
00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 40)
00:14.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 50)
00:14.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 50)
00:14.2 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 51)
01:00.0 VGA compatible controller: ATI Technologies Inc RV280 [Radeon 9200 SE] (rev 01)
01:00.1 Display controller: ATI Technologies Inc RV280 [Radeon 9200 SE] (Secondary) (rev 01)