I've had the same problem - I finally realized it was becuase I polished the car so soon after washing it, that there was still really small places that were still damp - like the seal around the sunroof, under trim, etc. When polishing, it would pick up this little bit of water - which doesn't mix with detailing products.
I'd say next time you decide to detail the car, let it dry off for a good 2 hours. Should fix the problems. Of course big daddy's suggestion is valid...and everyone should claybar their car sometime. It made a huge difference on my car.
