I have seen this since moving from radeonhd to radeon (about 1 year ago).
I'm on a gentoo 32 bit, currently kernel 2.6.32, xorg 1.7.6, radeon git, UMS.
Never used compiz; I have a radeon mobility X1400.
haven't tried the display watermark stuff (don't even know if it applies to UMS).
I have seen this since moving from radeonhd to radeon (about 1 year ago).
I'm on a gentoo 32 bit, currently kernel 2.6.32, xorg 1.7.6, radeon git, UMS.
Never used compiz; I have a radeon mobility X1400.
haven't tried the display watermark stuff (don't even know if it applies to UMS).