Windows 10 x64
Nvidia gtx 460
Short description of error
MultiSample setting in user preferences causes the surface projection on the freehand curve tool to fail after editing any mesh in the scene.
Going into and out of edit mode without making any changes doesn't cause problems.
Exact steps for others to reproduce the error
Here's a video
Set the multisample setting under the system tab in user prefs to anything. Save prefs. Restart Blender.
Add a curve and a few models to draw on.
Go into editmode on the curve and set the projection to surface.
Draw a curve on the model. (it will work as expected)
Edit any of the meshes.
Draw another curve. (this time it will fail)