Muller, get a small sharp pin and prick the decals where they are not sitting correctly and apply a tiny bit of decal softener at these points this should help settle them a bit better and get rid of the 'air' or silvering affect.
Do it on the lower surfaces first to see how it reacts, so if you have a problem it won't be obvious....The tamiya decals I don't think will react like other decals and wrinkle in the first stage of helping stick down the decal.
As you apply the softener you will see it flow under the decal, carefully dab the excess away with a tissue and repeat, carefully! This should fix it...