A side effect of enabling the l10n updates is that en-US nightly builds that finish after 7AM PDT (which is when l10n nightly repackages are triggered) will take longer to receive an update offer. Specifically, this happens mainly for win32 builds since they take way longer to finish.
Currently there is only one machine that checks for pending updates to be generated and it generates them all pending jobs in one shot, pushes the snippets live and then checks again for more pending jobs.
The problem is that if the system picks X number of pending updates it will process them one by one but without pushing any snippets and partial MAR files live until it finishes with all X jobs.
Therefore, since the en-US nightly for win32 finishes after 7AM, it falls in the bucket of pending jobs and it can take two or three hours before the snippets are pushed live.
To fix this regression we have decided to have a temporary fix to our update generation system until we do the long term infrastructure changes.
To follow the work on this fix please follow the work on bug 511901.
We are really sorry for any inconvenience and we would like to have it fixed as soon as possible.
This work by Zambrano Gasparnian, Armen is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.