WELL
only thing i suggest you can do so you don't run around chasing your tail on this, is be home next time we get the wind/rain you say it needs to show the leak.
Maybe we can take a look sunday ?
Stop at home depot, lowes ect, pick up a little jug of roofing tar.
when it rains, go in the attic, watch where the water comes in, you may have to search for it, cause water can travel along ways before it drips down. then you need to fill the hole from outside and inside. May want to drill a small hole where the water is coming in, from inside out...stick an object in the hole so you can see it when you go on the roof, remove the object, and fill it with a little bit of tar, then go inside in fill that area as well.
but finding the actual inlet of a little leak is a pain in the arse.....i would chack all caps, all valleys, and all tinned, flashing area's around your chimney's ect...for adequate tar, sealant.