Graphics corruption using sideport memory

When using only the sideport memory with a ATI HD 3300 there are small corruptions in the graphics around window borders. Windows that have moving content (scrolling lines in terminal or videos) give more corruption. It looks just like horizontal lines of pixels offset. When sideport+uma is enabled there are no corruptions.

Ubuntu 10.04 Daily from March 28
fglrx installed using apt and aticonfig --initial

Linux Desktop 2.6.32-17-generic #26-Ubuntu SMP Sat Mar 20 02:23:45 UTC 2010 x86_64 GNU/Linux
fglrx:
  Installed: 2:8.721-0ubuntu5

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: fglrx 2:8.721-0ubuntu5
ProcVersionSignature: Ubuntu 2.6.32-17.26-generic 2.6.32.10+drm33.1
Uname: Linux 2.6.32-17-generic x86_64
NonfreeKernelModules: fglrx
Architecture: amd64
Date: Sun Mar 28 14:40:28 2010
DkmsStatus: fglrx, 8.721, 2.6.32-17-generic, x86_64: installed
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Alpha amd64 (20100328)
MachineType: System manufacturer System Product Name
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-17-generic root=UUID=11d87f11-934e-4982-a4cc-79fe6ff8deff ro quiet splash
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: fglrx-installer
dmi.bios.date: 09/18/2009
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1504
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: M3A78-T
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1504:bd09/18/2009:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnM3A78-T:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer
system:
 distro: Ubuntu
 codename: lucid
 architecture: x86_64
 kernel: 2.6.32-17-generic