DS is 15 months and I have BBB, BB magicalls and Bumgenius V3. The BBB gives him a bit of a rash so I have microfleece liners to keep him drier (which works fine) but both the magicalls and the BG are leaking (the BG really badly).
I don't think you have an absorbancy issue there as much as the fleece liner and the fleece or suedecloth inner of the nappy are working together and creating a barrier and the wee can't soak through to the absorbant layer so it's just running out the leg. Try using disposable liners with the cream and see how that goes. They will protect the nappy from the cream but not create that layered effect of the fleece.
Seeing as the BBB's don't have a fleece inner it wouldn't be happening with that one.