subversion (1.6.5) and - depending on it - mr. developer complained about some strange missing ancestry information, when I tried to commit in this directory tree:

toplevel/

  .svn/

  ...

  2ndlevel/

      (no .svn here)

      ...

      3rdlevel/

          .svn/

          code_to_commit

Trying

cd 3rdlevel
svn commit -m 'bla'

produced the error

svn: '2ndlevel' has no ancestry information

which I didn't understand,  since the 3rdlevel was a check out of it's own, not related to the toplevel.

subversion seems to look up .svn/ directories along the complete absolute path of the directory which is checked in and hasn't recorded that 3rdlevel/ is a "checkout root".

The solution: removing the .svn in the toplevel dir (putting a reasonable one in 2ndlevel by adding it to svn might have worked, too).