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
10.WorkBench:> version WorkBench:Kickstart/PCIGraphics.card
Also what do you have in Devs:Monitors ?
PCIGraphics PCIGraphics.info Radeon
I use Radeon for my Devs/Monitors driver with the following tooltypes
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).