I just did 5 cold boots with a HD4850 and both version 0.55 and version 0.32 of the driver.
All 10 boots were ok.
Check your versions of the following :
10.WorkBench:> version WorkBench:Kickstart/siliconmotion502.chip
SiliconMotion502.chip 53.10
10.WorkBench:> version WorkBench:Kickstart/PCIGraphics.card
PCIGraphics.card 53.5
Also what do you have in Devs:Monitors ?
dir WorkBench:Devs/Monitors/
PCIGraphics PCIGraphics.info Radeon
Radeon.info
I use Radeon for my Devs/Monitors driver with the following tooltypes
CMPLENGTH=6
BOARDNAME=Radeon
DDCMODE=All
(VSYNCMIN=60)
(VSYNCMAX=60)
(HSYNCMIN=31000)
(HSYNCMAX=85000)
(MODE=640x480@60)
(MODE=800x600@60)
(MODE=1024x768@60)
(MODE=1280x720@60)
(MODE=1280x800@60)
(MODE=1280x960@60)
(MODE=1280x1024@60)
(MODE=1440x900@60)
(MODE=1600x900@60)
(MODE=1600x1200@60)
(MODE=1680x1050@60)
(MODE=1920x1080@60)
FAKENATIVEMODES=No
INTERRUPT=Yes
Interrogative wrote:In other words, I should buy the updated RadeonHD driver from A-Eon. I am currently using the last free update (0.32).