Linux you are so funny:

[root@www typo3_src]# rm typo3_src-4.2.8/
rm: cannot remove directory `typo3_src-4.2.8/': Is a directory
[root@www typo3_src]# rmdir typo3_src-4.2.8/
rmdir: typo3_src-4.2.8/: Not a directory
[root@www typo3_src]# rm typo3_src-4.2.8/
rm: cannot remove directory `typo3_src-4.2.8/': Is a directory