I tried this and it does slice . There are some missing elements in the support structure here and there, but it works.
There are many errors in the mesh which can be fixed, but they don't prevent Slic3r from generating a Gcode. I fixed the model anyway, so try to slice it now.
Additionally, the support structure thickness, seems to be about .2mm. That's less than half the minimum extrusion width of the Solidoodle., so when you design your structures you should make sure the walls are at least .5mm thick.
Newer versions of Slic3r have an option to detect thin walls, but if that's off you'll have problems.
BTW, what version of Slic3r are you using. I'm currently using v.1.1.7 and it can handle it just fine.
Post's attachmentscube test (repaired).stl 849.89 kb, 4 downloads since 2015-01-20
You don't have the permssions to download the attachments of this post.
To print or, 3D print, that is the question...
SD3 printer w/too many mods, Printrbot Simple Maker Ed., FormLabs Form 1+
AnyCubic Photon, Shining 3D EinScan-S & Atlas 3D scanners...
...and too much time on my hands.