Isolate selection script crashes Outliner

[Pjanssen]

What steps will reproduce the problem?

1. Enter isolate selection mode with the Outliner opened
2. Close isolate selection mode.

What is the expected output? What do you see instead?
Should not affect Outliner. Instead, it crashes.

What version of the product are you using? On what operating system?
2.0.96

Please provide any additional information below.
See crash report #20110907_533, #20110929_556, etc.