DS2 has a incredibly long body. I had this problem with ds1, but ds2 also has quite short legs. Most babygrows are too short in the body length. I have got some Mothercare ones that are fine in the body length, but the legs are so long when ds pulls his legs up they get stuck in the leg.
Was going to buy some Next ones to try but wondered if anyone else had this problem and where they bought theirs from.