I can confirm having the bug in 12.04. However, I also managed to get rid of this.
After setting directory to ~/Pictures/Photos via dconf-settings, Shotwell behaved as in comment #12, the input field in preferences is set to "(None)". The structure of the Photos dir was:
2005/
2006/
...
2012/
some_text_file
I removed some_text_file, so only year folders were left. After restarting Shotwell, Photos folder is correctly displayed in preferences and I can import photos to that folder.
I can confirm having the bug in 12.04. However, I also managed to get rid of this.
After setting directory to ~/Pictures/Photos via dconf-settings, Shotwell behaved as in comment #12, the input field in preferences is set to "(None)". The structure of the Photos dir was:
2005/
2006/
...
2012/
some_text_file
I removed some_text_file, so only year folders were left. After restarting Shotwell, Photos folder is correctly displayed in preferences and I can import photos to that folder.