'svn switch' and already switched dirs

Hi,

In a couple of working copies, we have the following setup:

/release-1.0.0.1 (checked from /branches/release/release-1.0.0.1)
    /alpha/beta
    /alpha/gamma -> (switched to /trunk/alpha/gamma)
    /alpha/delta
    /alpha/delta/epsilon -> (switched to /trunk/alpha/delta/epsilon)

If I run 'svn switch '/branches/release/release-1.0.0.2' from the root
directory), I would expect SVN to leave the already existing switched
directories alone. However, it switches all directories (so
/alpha/gamma is now switched batch to /branches/release ... )

Is this expected? Is there a switch to prevent this from occurring?

And, yes, I know that externals could be used for this as well, and if
we can't work around the above issue, then we might need to go to
that.

Cheers,

---
Daniel Becroft