Hrm. Having nothing but problems with TortoiseSVN 1.7.1.. two different upgraded repositories are now stuck in an endless "you must clean..", clean says "You must unlock to clean" and of course trying to unlock fails and asks you to clean. I guess I should be blaming svn 1.7.X, not the Tortoise guys as it happens from the command line too.
Going back to 1.6.X…
The upgrade of working copies often fails. But a fresh checkout will get rid of all your problems.
I cannot agree more. 1.7.X is nothing but problems.