After an effortless upgrade to Snow Leopard and while running SpamSieve 2.7.5, I can no longer manually designate messages in the Inbox as spam, nor designate messages in the Spam mailbox as good. That is, selecting the message(s), and the selecting the appropriate menu item (or key combination) no longer moves the message(s) in either direction. They do not turn gray.
Meanwhile, SpamSieve continues to filter in automatic mode.
I have searched the forums, but find no mention of this problem for over a year. And I have checked permissions, but all is as it should be. Any suggestions greatly appreciated.