Subversion update says Akismet is “not a working copy”

I converted my blog to subversion a while back. When I was preparing to upgrade to 2.6.1, I noticed several plugins had the “upgrade automatically” option. So, I clicked on this for them, including Akismet to bring it from 2.1.5 to 2.1.6.

Then, I did the subversion upgrade:

svn sw http://svn.automattic.com/wordpress/tags/2.6.1/ .

Everything went fine except I saw this message at the end, which is presumably related to the fact that the automatic upgrade of Akismet overwrote some Subversion info:

Fetching external item into ‘wp-content/plugins/akismet’
svn: ‘wp-content/plugins/akismet’ is not a working copy
svn: Can’t open file ‘wp-content/plugins/akismet/.svn/entries’: No such file or directory

It appears the upgrade went OK, but I’m wondering if I’m going to get this message every time I upgrade in the future and if there is any easy way to get Akismet back in a state such that Subversion knows about it.

Also, assuming the automatic plugin upgrade caused this Subversion problem, it might be nice to have a disclaimer about this to prevent other users from doing this in the future.

Thanks in advance.