Hi! Looks like I've encountered a bug in Slic3r!
Slic3r 1.1.6 in Repetier-Host v1.00 RC2. (yeah, not the newest, but quite recent =)
I was trying out spiral vase mode, the model is just a solid 48-segment cylinder. And the slicer output showed up as total garbage in Slic3r (see attachments). At first, I even thought it could be Repetier-Host visualization bug, so I've even tried printing the garbage to confirm.
After a lot of tinkering (even tried Cura, it didn't work, but it's a whole separate issue) I've found that if I switch off the relative E distances, the thing slices perfectly. I have switched to relative E distances quite a while ago and had no problems till now. Funny, isn't it?
See complete slicer setup and the model in attachments. Some settings may have been affected by Repetier-Host, I'm not 100% sure.