Well, I'm sure there will be a few pleased people today. It turns out that those members stuck on the Budding Member level actually shouldn't have been. For a strange reason, the code was ignoring those unranked members when running the algorithm. This wouldn't have effected the climb in rankings for anyone who already had Full Member status, but it has affected those stuck on the Budding Member status.
It is fixed now with some very interesting results. Niels (bentivogli) and Mike (MikeyBoab) should be particularly pleased as they have risen to Respected Member without even ever touching Full Member status (and may I add that neither are far from Guru either..)
Apologies to all of you.. hopefully everything makes more sense now