Leaking legs!

I've been having some trouble with my pockets - PBPDs and WN one size, and even my normally uber-reliable Green Kids let me down the other day (I had a quite new Blueberry insert in it though so I am blaming that)! They leak wee round the legs, no matter how carefully I do them up so that I can't see any gaps. My son is 10 weeks and wees for England, but sometimes - particularly with the PBPDs - it seems that one wee is enough to leak out, the insert itself is barely damp. Why is this and how do I stop it? I do seem to find it worse on nappies with a minky inner - the fleece ones are much better. I've just bought a few more Green Kids bamboo inserts, as I've found them the best so far, so hopefully that will really help. I've been using Blueberry ones up until now and I just don't think they are up to the job!
Would doing a strip wash help? I don't think it can be a detergent build up as the nappies are still fairly new.
Thanks in anticipation!

If the nappies are new it could be that they're not washed up to full absorbency yet.
I've also heard that minki takes longer to 'stay dry' than fleece does. Maybe your little man just needs fleece?

I think you are right about the fleece...but also, I just tried the PBPDs on him again and realised - they're just too big for him! He's a big baby for 10 weeks, but he's long rather than chubby and they are mediums and gaping round his thighs. Guess I'll just have to wait for him to grow into them!

Does sound like it is just the fit that is the problem. Sometimes nappies just don't suit their shape either. Hopefully they will be a nice fit on him soon and you won't have any leaks