I've had this problem in both 2008 and 2009. Normally, when doing a 3d sketch, you can change the plane you are working on by pressing Tab. However, it is common for this to just stop working. Pressing Tab has no effect, and I am stuck in what ever plane it happened to be in at the time.

Do others have this? Is there a way to force SW to change to a different plane, other than Tab?

Joe Dunfee