I buy mine at Metro Threads and have not had any problems with their bobbin or embroidery thread. Prices and shipping are excellent.
Jerri
Like anangel, I get all of my threads stabilizers and some of my tools from Allstitch. I have never had an issue, every order has been correct and delivered in a timely fashion.
I buy most of my stabilizers and NEBs pre-wound bobbins from www.allstitch.net. Reasonable prices and quick delivery. I like Metro threads. I much prefer pre-wound bobbins, than winding my own, and my machines seem to like them, too.
Hugs, Angel