Today I found some time to try sketchy edges on other systems, and this is the result :
On my main system, a desktop with Nvidia Geforce 6150SE videocard I have Sketchup 8.0.16846 and wine 1.5.24: skechy edges does not work.
On a Dell latitude D620 laptop with Ubuntu 12.04, sketchup 8.0.16846 and wine 1.5.25 sketchy edges work perfectly.
This gave me some hope, so on my desktop, I upgraded wine to 1.5.25 to see what happened.... unfortunately I still have no sketchy edges.
As a last test I took a Dell latitude D630 with fedora 18, sketchup 8.0.16846 and wine 1.2.24 : no sketchy edges either, after upgrading to wine 1.5.25 still no sketchy edges...
So it seems that the problem is not only related to Sketchup and Wine, both my fedoras, on very different hardware seem to have the problem while ubuntu, on similar hardware as Fedora18 seems to work fine.
Anyway, the sketchy edges are not a terrible issue for me, and whenever I need them, I can go back to my ubuntu laptop....
Geert