System Information
Mac OS X 10.9.5, 2 x 2.8 GHz Quad-Core Intel Xeon, 16 GB, NVIDIA GeForce GTX 660 3072 MB
Blender Version
Broken: 2.73RC, 2.72
Worked: ?

Short description of error
Remesh/motion blur mess when used together on deforming mesh.

Exact steps for others to reproduce the error

1. F12 render to see character as intended (N.B. character ultimately to be rendered as volumetric, hence remesh used to remove volumetric intersection artefacts)
2. Shift Z in viewport to see rendered view - all OK
3. Enable 'Motion Blur' in Render panel
4. F12 render to see character in nasty remesh Shelob web
5. Disable remesh modifier and F12 render - all OK again.

Not sure if this is a know issue, or whether I'm just expecting too much of remesh. It certainly does the job for what I'm doing until motion blur is enabled.

I haven't yet reproduced this yet on a simple model, but this .blend gives a nice clear demonstration.

For now I suppose I need to try compositing vector blur again.

Thanks and Happy New Year!