I have hit the key accidently instead of return and poof, Safari quits unexpectedly. Forward slashes are no problem but Backslashes cause an instant quit. It doesn't happen all the time, but just today I hit the key accidently and Safari quit. I reloaded it up again and the first thing I did was type a backslash. Again instant quit. Upon trying it again, it didn't quit.
The Backslash must be typed in the Google search box to cause the sudden quit.

Safari 4.0.3 (5531.9)
The Backslash must be typed in the Google search box to cause the sudden quit.

Safari 4.0.3 (5531.9)