Maybe,you forgot to add the EDID to the RadeonHD.kext.
Then should all be fine,without the sleepmode.
I finally solved my problem. For anyone experiencing the same problem... I downloaded the RadeonHD.kext (05/13/2010) from topic http://www.insanelym...howtopic=190586
Simply copied the info.plist from the contents folder of the RadeonHD I had to the one from the topic, and now, problem solved.
Just wanted to share. Thanks Michael
Dell Inspiron E1505/6400
Ati Mobility x1400 (Full Resolution 1280x800) QE/CI Enabled without Mouse tearing (Perfect!!!)
Snow Leopard 10.6.3
Core 2 Duo