Hi, I have infused a few parts now and up untill this point I have been really pleased with my results, however the last part I have made has ended up being a total disaster basically it's a bit more complicated than any of the other parts I have tried to make, it has quite tight corners and it is quite deep. all around the corners i'm getting big air pockets, why is this happening i have got perfect vacuum so how come there is air in there? help please it's driving me crazy!