To reproduce this bug:

1) Open TextMate 2 Alpha

2) View -> Show File Browser

3) Try to change default directory from user home directory to smith else 

4) TextMate 2 Alpha goes crazy and tries to iterate and open in a file browser every directory under home user directory.

The screenshot:

http://dl.dropbox.com/u/2658449/Screen%20Shot%202012-01-21%20at%207.21.14%20PM.png