I'm currently migrating one machine from stable to testing, and because my network connection seems to be a little flakey, every so often a package download is failing over from mirror.dacentec.com to repo.manjaro.org.uk, where it gets a 404 error and then fails over to the Brazilian mirror.
Is there a problem with updates on the UK mirror, as I don't see any packages newer than 28 Dec 2012 when I look at the pool directory?