I've updated the original URL, because it's moved. Both it and the one I've attached later still scroll very slowly (Linux/i686 2001080106}.
I think that it is caused by BODY tag definition that in both cases specifies
background-attachment : fixed;
which obviously is more gfx-heavy. Considering much slower gfx speed in Linux Mozilla, this is probably the reason you're not seeing it under Windows.
I've updated the original URL, because it's moved. Both it and the one I've
attached later still scroll very slowly (Linux/i686 2001080106}.
I think that it is caused by BODY tag definition that in both cases specifies
background- attachment : fixed;
which obviously is more gfx-heavy. Considering much slower gfx speed in Linux
Mozilla, this is probably the reason you're not seeing it under Windows.