Comment 14 for bug 643787

James:

What appears to have happened is that in configuring lucid-proposed as suggested in the SRU related instructions (restricted to install only what is requested) that aptitude was somehow unable to completely resolve all of the dependencies. by configuring lucid-proposed as a normal repository got a successful upgrade (but unfortunately installed many other un-related packages that are in proposed on the test system.

I'm retracting my tag change and re-running the validation.