I have Sketchup 8 pro but the collada export doesn't work for SL either, crashes again and again and again. I think it has to do with Sketchup 8 exporting to a newer Collada format (they changed the Collada export in Sketchup 7.1 and on).
What does (kinda) work however, is saving a Sketchup 8 file as Sketchup 7, then open it in Sketchup 7 and export the .dae from there, that's the only way i've found to get meshes made in Sketchup 8 into SL.