[Trisquel-users] Cannot activate Desktop effects

[zacharias]

When I right click the desktop; Change Desktop Background - Visual Effects  
and click Normal I get a popup; Desktop Effects Could Not Be Enabled... i had  
ububtu b4, and it did ran quite good.
what can i do to solve this and stick with trisquel forever? ;)
my graphic agp is a GeForce 6600.
kudos