This problem appeared already with SuSE 10.0 (from DVD). It still appears with the current xorg-x11-server / -driver rpms from the betas. It did not appear with XFree86 (i.e. SuSE 9.0/9.1).

When the 'Virtual' statement is used in xorg.conf (Subsection "Display") touching the borders of the screen (with the mouse pointer) moves the viewport. However, if the right or lower border is touched for a slightly longer time in the most right/lower position, the screen gets garbled: its contents will depend on further mouse movements. All pixels which have greater y-coordinate than the mouse pointer are black; the other lines of the screen are moving horizontally, the speed varying somehow with the x-position of the mouse pointer. It is only a graphics problem, the system remains completely responsive (standard 80x25 console works, too, but not fb console).

The system I'm using is a Shuttle SB52G2 with i845GV chipset. The problem is reproducible with SuSE and vanilla kernels, suspending from the garbled screen and resuming (via suspend2) generally restores a correct screen state. It does not seem to depend on the window manager (under SuSE 10.0, I've reproduced things with kde, afterstep, and blackbox - since I've installed the current X, the alternative WMs can't be loaded for a reason that I haven't been able to track down).


extract from xorg.conf:

Section "Screen"
  DefaultDepth 24
  SubSection "Display"
    Depth      15
    Modes      "1280x1024" "1280x960" "1280x800" "1152x864" "1280x768" "1024x768
" "800x600" "768x576" "640x480"
#    Virtual    1600 1200
  EndSubSection
  SubSection "Display"
    Depth      16
    Modes      "1280x1024" "1280x960" "1280x800" "1152x864" "1280x768" "1024x768
" "800x600" "768x576" "640x480"
#    Virtual    1600 1200
  EndSubSection
  SubSection "Display"
    Depth      24
    Modes      "1280x1024" "1280x960" "1280x800" "1152x864" "1280x768" "1024x768
" "800x600" "768x576" "640x480"
#    Virtual    1600 1200
  EndSubSection
  SubSection "Display"
    Depth      32
    Modes      "1280x1024" "1280x960" "1280x800" "1152x864" "1280x768" "1024x768
" "800x600" "768x576" "640x480"
#    Virtual    1600 1200
  EndSubSection
  SubSection "Display"
    Depth      8
    Modes      "1280x1024" "1280x960" "1280x800" "1152x864" "1280x768" "1024x768
" "800x600" "768x576" "640x480"
#    Virtual    1600 1200
  EndSubSection
  Device       "Device[0]"
  Identifier   "Screen[0]"
  Monitor      "Monitor[0]"
EndSection

Section "Device"
  BoardName    "i845"
  BusID        "0:2:0"
  Driver       "i810"
#  Driver       "fbdev"
  Identifier   "Device[0]"
  Option       "usevnc" "no"
  Screen       0
  VendorName   "Intel"
EndSection


hwinfo --gfx:

spadina:/home/cba #  hwinfo --gfx
11: PCI 02.0: 0300 VGA compatible controller (VGA)
  [Created at pci.277]
  UDI: /org/freedesktop/Hal/devices/pci_8086_2562
  Unique ID: _Znp.zNkBCGSdn4D
  SysFS ID: /devices/pci0000:00/0000:00:02.0
  SysFS BusID: 0000:00:02.0
  Hardware Class: graphics card
  Model: "Holco Enterprise Co, Ltd/Shuttle i845"
  Vendor: pci 0x8086 "Intel Corporation"
  Device: pci 0x2562 "i845"
  SubVendor: pci 0x1297 "Holco Enterprise Co, Ltd/Shuttle Computer"
  SubDevice: pci 0xfb52
  Revision: 0x03
  Driver: "intelfb"
  Memory Range: 0xe0000000-0xe7ffffff (rw,prefetchable)
  Memory Range: 0xe8100000-0xe817ffff (rw,non-prefetchable)
  IRQ: 17 (81248 events)
  I/O Ports: 0x3c0-0x3df (rw)
  Module Alias: "pci:v00008086d00002562sv00001297sd0000FB52bc03sc00i00"
  Driver Info #0:
    XFree86 v4 Server Module: i810
  Driver Info #1:
    XFree86 v4 Server Module: i810
    3D Support: yes
    Extensions: dri
  Config Status: cfg=yes, avail=yes, need=yes, active=unknown

Primary display adapter: #11