I know this reply is kind of late, but I’m still looking into this myself.
I’ve had the problem back with Daz 4 as well. When I got a hold of their support team, I was told that COLLADA (.dae) files are a rough standard. Not sure how much I believe that or if I mis-understood support.
Google / Trimble / whoever currently owns Sketchup says that it uses the COLLADA 1.4 specifications and schema (as of 10/16/2012 at least). I couldn’t find a similar specification on DAZ. The closest I’ve come is to notice that Daz never puts just “COLLADA” files, it’s always “DAZ COLLADA”, which makes me think they might be the ones breaking the format. Don’t know since I don’t have any other 3D editor to try exporting with.
Hopefully someone comes along and fixes this, since COLLADA is really the only way to transition between the two (without having Sketchup Pro).