I have an ATI radeon IGP 340M (Chip ID 1002:4337) that works really nice with the open source "ati" driver and compiz ALWAYS worked very well since Feisty.
According to a problem on some ati cards as reported in Bug #197135, open source "ati" driver is going to be blacklisted for compiz in Hardy (on laptops).
My card is not supported by fglrx (5 years old card) so I won't be able to use compiz by default in Hardy.
To sum up, this card need to be whitelisted in order to use compiz by default in Hardy, as it always did before.
lspci -vn attached.
[WORK-AROUND]
Add "SKIP_CHECKS=yes" to either /etc/xdg/compiz/compiz-manager or ~/.config/compiz/compiz-manager
[Summary of what's already been reported -- please update if your ati works]
1002:3154
1002:4336 Paul Roberts/shemgp: Radeon Mobility U1
1002:4337 Jarvis/Sergio Zanchetta: Radeon IGP 330M/340M/350M
1002:4c57 Chad Bernier/others: M7 LW [Radeon Mobility 7500]
1002:4c66 Thomas Wolfe: Mobility 9000 (M9) Lf (AGP)
Aaron Bentley: ATI Technologies Inc Radeon RV250 [Mobility FireGL 9000] (rev 02)
Timo Jyrinki: Radeon RV25 [Radeon Mobility 9000]
1002:4e50 Miguel Martinez/others: RV350 [Mobility Radeon 9600 M10]
Tomas Nilsson: M7 LW [Radeon Mobility 7500]
Matti Airas: Mobility Radeon 9600
1002:4e56 fuoco: M11 NV [FireGL Mobility T2e]
1002:5460 Vladimir Dobriakov
1002:5653 Tormod Volden: ATI Mobility Radeon X700 (M26) (PCIE)
1002:5835 dienarr: RS300M AGP [Radeon Mobility 9100IGP]
I join this. I was very surprised by the decision to blacklist radeon/ati - it works for me since a very long time.
I have a radeon 9550 in an iBook G4. relevant lspci part: (from lspci -nn)
0000:00:10.0 VGA compatible controller [0300]: ATI Technologies Inc M11 NV [FireGL Mobility T2e] [1002:4e56] (rev 80)