My weight increased as I tried statins again from June 2013. Was on Lipitor, however I have stopped them again as the chest pains I had first time round came back again, the day I stopped taking them my heart pains stopped. However, I wonder if you have started taking a statin at all, as weight gain is also written on some statins as a side effect....since stopping the statin my weight has naturally dropped.. Even with eating moreover Xmas and not doing much physical work.
The pump does allow more freedom really to eat more to be honest, have a look at your total insulin doses that you were averaging on mdi, and compare to today's total insulin dosages... If you aren't honestly eating more, then your totals should be less now than when you were on mdi.
Are you taking any different drugs that can be causing water retention?