testsuite problems

hello,

i was running 'make test' on v1.5.3.1-109-gacd6917 and i hit the
following issue:

*   ok 6: validate file modification time
*   ok 7: git get-tar-commit-id
*   ok 8: extract tar archive
*   ok 9: validate filenames
*   ok 10: validate file contents
*   ok 11: git tar-tree with prefix
*   ok 12: extract tar archive with prefix
*   ok 13: validate filenames with prefix
*   ok 14: validate file contents with prefix
*   ok 15: create an archive with a substfile
*   ok 16: extract substfile
*   ok 17: validate substfile contents
*   ok 18: git archive --format=zip
*   ok 19: extract ZIP archive
*   ok 20: validate filenames
* FAIL 21: validate file contents
        diff -r a d/a
*   ok 22: git archive --format=zip with prefix
*   ok 23: extract ZIP archive with prefix
*   ok 24: validate filenames with prefix
* FAIL 25: validate file contents with prefix
        diff -r a e/prefix/a
*   ok 26: git archive --list outside of a git repo
* failed 2 among 26 test(s)
make[1]: *** [t5000-tar-tree.sh] Error 1
make[1]: Leaving directory `/home/vmiklos/git/git/t'
make: *** [test] Error 2

$ tar --version
tar (GNU tar) 1.18

$ diff --version
diff (GNU diffutils) 2.8.1

maybe these versions are too new or old? if i missed any needed info,
please let me know.

thanks,
- VMiklos