Quick note - in SA1 you will be on different equipment from Welshchris who is on Cwmbwrla kit not Swansea.
The condition of needing to manually renew IP affects me on the 50Mbit modem as well. The ready light flashing is just a cosmetic bug and shouldn't be worried about.
This withstanding it sounds like whenever you are load balanced across from one downstream to another you are having to manually renew IP - most annoying for sure but nothing to do with Welshchris and his issue.
It seems to be a bit random, some customer kit is just fine with the modem dropping sync and comes back online just fine, some isn't.
EDIT: Also your post is another post showing what a 'mare this thread is. So many causes for the same symptom. It's almost like trying to say every time someone sneezes it has to be swine flu because people with swine flu sneeze
