Garbage on screen (Sam440 Flex and Radeon 9250)

[samo79]

In some case some garbage appear on screen .. it though it was solved and indeed it happened more frequently in AmigaOS 4.1 Update 6 and older ... however seems not completely fixed even in AmigaOS 4.1 Final Edition Update 1

My machine is:

Sam440 Flex 800
Radeon 9250
AmigaOS 4.1 Final Edition Update 1