Data on file exchange partition is owned by 1000 and locked. How can I unlock this in OS X? 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?
Unlocking the file
You can unlock files from within the terminal using the chflags command with nouchg:
sudo chflags -R nouchg Bilder

According to the man page for chflags:

uchg is the user immutable flag
no in front of a flag removes the flag: nouchg

Preventing this from happening in the future
A general solution would probably be to avoid handling permission altogether and using NTFS or FAT for an exchange partition.
However, I specifically voided such a solution (FAT32) this time, because I encountered serious errors the last time.