I have created a file exchange permission that both OS X Lion and Ubuntu 12.04 can write to and read from. This partition is formatted as...
Apple_HFS Exchange
...with journaling disabled. I have copied a folder from Ubuntu onto that partition. This folder appears as locked in OS X and I am not able to unlock this folder. The option is greyed out.

The permission of this folder are:
drwxr-xr-x 4 1000 1000 136 11 Mai 14:43 Bilder
- How can I unlock this file in OS X?
- How can I prevent this from happening in the future?