Git doesn't work on Ext3 partition

[radly]

I have an ext3 partition where I put shared data. I'd like to be able to use the Git version control system there, but I cannot achieve a commit. I have no problem doing so on the HFS+ (OSX) file system, but doing so on the ext3 file system returns this error:error:

unable to create temporary sha1 filename : Not a directory
fatal: failed to write commit object

Have you any idea what might be the problem? I have permissions set to 777 (read/write/execute for user, group, and other).