[xmonad] Receiving duplicate bug reports

Hi all. A few days ago I had to resubscribe to xmonad@ (i.e. change the subscribed email address). Since that, I receive duplicate message from Google Code BTS. There's just a little difference in the headers. I've attached an example of duplicates. Note that both are delivered to new email address (old was hosted at GMail). Ordinary message to mailing list aren't duplicated. Does anyone have an idea what to do with it? Sure, I can configure my MDA to drop such duplicates, but what could cause such behaviour? -- Roman I. Cheplyaka http://ro-che.info/