Xinerama does not work with SUNFFB and MatroxMillenium on Sparc64

[Detlef <dh_hh_remove@web.de>]

Hi out there, 

I have an Ultra Sparc 30 with a Creator 3D and Matrox Millenium installed.
Both work fine in Doublehead mode but Xinerama says: 

could not create connection block info

No my screens are both setup using 1280x1024x24. 

I dug a bit deeper and xdpyinfo shows a slight difference between the
visuals regarding the RGB masks and the largest cursor (see the partly cut
output of xdpyinfo below). I suspect the RGB masks the reason for the
screens being incompatible. 

Has anyone an Idea how I could circumvent this and start using Xinerama?

regards
 Detlef 

Matrox: 
  dimensions:    1280x1024 pixels (325x260 millimeters)
  resolution:    100x100 dots per inch
  depths (7):    24, 1, 4, 8, 15, 16, 32
  root window id:    0x52
  depth of root window:    24 planes
  number of colormaps:    minimum 1, maximum 1
  default colormap:    0x20
  default number of colormap cells:    256
  preallocated pixels:    black 0, white 16777215
  options:    backing-store NO, save-unders NO
  largest cursor:    1280x1024
  current input event mask:    0xfa2033
    KeyPressMask             KeyReleaseMask           EnterWindowMask
    LeaveWindowMask          ButtonMotionMask         StructureNotifyMask
    SubstructureNotifyMask   SubstructureRedirectMask FocusChangeMask
    PropertyChangeMask       ColormapChangeMask
  number of visuals:    4
  default visual id:  0x22
  visual:
    visual id:    0x22
    class:    TrueColor
    depth:    24 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff0000, 0xff00, 0xff
    significant bits in color specification:    8 bits


Creator 3D
  dimensions:    1280x1024 pixels (325x260 millimeters)
  resolution:    100x100 dots per inch
  depths (7):    24, 1, 4, 8, 15, 16, 32
  root window id:    0x54
  depth of root window:    24 planes
  number of colormaps:    minimum 1, maximum 1
  default colormap:    0x38
  default number of colormap cells:    256
  preallocated pixels:    black 0, white 16711422
  options:    backing-store NO, save-unders NO
  largest cursor:    64x64
  current input event mask:    0xfa2033
    KeyPressMask             KeyReleaseMask           EnterWindowMask
    LeaveWindowMask          ButtonMotionMask         StructureNotifyMask
    SubstructureNotifyMask   SubstructureRedirectMask FocusChangeMask
    PropertyChangeMask       ColormapChangeMask
  number of visuals:    4
  default visual id:  0x3a
  visual:
    visual id:    0x3a
    class:    TrueColor
    depth:    24 planes
    available colormap entries:    256 per subfield
    red, green, blue masks:    0xff, 0xff00, 0xff0000
    significant bits in color specification:    8 bits