svn import not detecting branch

Hi,
I am trying to import a svndumpfile.
The trunk import went Ok, but no baselines were created for the branches.
I manually created the baselines at the correct point in history.

Now when I try to import a branch it fails with a server error and in the logfile
I get the error:
Parent '' has multiple children with the name '######'
If I understand the documentation, the wizard should detect that it is a branch import and will probably act different.

It might be a problem with the svn layout. Those branches were created in the root and not in the branches directory.
svn layout:
\branchA
\branchB
\tags
\trunk

Any ideas on how to import the branches?