**System Information**
Windows 7 64bit. geforce gtx 770
**Blender Version**
Broken: 2.71
Worked: 2.70a
**Short description of error**
having a object with a shrinkwrap modifier targeting a object with a shape key, and pressing play (Alt+A) causes very high CPU usage
(7% usage with no shape key, to 100% usage with)
(you may need to open up Windows task manager and click on the performance tab to see it)
despite nothing in the scene being animated.
**Exact steps for others to reproduce the error**
on the default cube scene
add a flat plane mesh above the cube
give it a shrinkwrap modifier and have it target the cube
now give the default cube a shape key
press play
{F95719}
{F95720}