OS = Win 7 64-Bit
GPU = Firepro 7900
Blender 2.69 official
Short description of error
On a mesh model containing only quads, using the UV Unwrap Mode "Follow Active Quads" sometimes yields no result at all and appears to do nothing. Results are sporadic, but most of the time it does not appear to work.
Exact steps for others to reproduce the error
On the attached blend file, in the 3D view, press "U", then select "Follow Active Quads". Apply using any of the 3 modes, and there appears to be no result, whereas the UV map should change.