Regrading to the launchpad blog about downtime deployment schedule. a launchpad will maintenance it server by the time 13 July 2011,  that causes Launchpad’s web interface will be read-only.

Launchpad user will not available to update their package for around 90 minutes from 08.00 UTC on the 13th July. See the detail bellow or visit Launchpad announcement here :
Starts: 08.00 UTC 13th July 2011
Ends before: 09.30 UTC 13th July 2011