Stripes On Dual Head Displays

[jaz_mm]

Anyone seen this behaviour?

I have a dual head on a power mac G5 - in fact I have two such machines and both have the same 'feature'.

Some applications use 'striping' to highlight alternate lines of text (e.g. Navicat, Path Finder) and many windows use the pin striping effect in the window header bar.

On one display the striping displays fine, on the other it is missing. If you use grab then the 'grab' image shows the stripes. If you switch the display connectors over, the presence or absence of striping is determined by the DVI port the display is connected to.

If the striping is set to a color other than blue (if you are using the Aqua desktop) then only the blue part is removed and the stripe appears on the display in the color minus the blue portion.

If you mess around with the opacity of the stripe (Path Finder lets you do that) then you can get blue stripes on the display provided the opacity does not match some magic value.

Weird behaviour - looks like some kind of fault in the display driver or OpenGL engine?. Is it just my two machines or can someone else reproduce this. My machines both have ATI Radeon 9650 display adapters so maybe its down to that.

I can find no reference from anyone else to this effect so I was beginning to wonder if it was me!