Birdnesting only with Coats and Clark Thread?

I have a Viking (Emerald 183 if that matters) and always use Gutterman thread.  I've never really had a problem with birdnesting before.  I am making a top for a friend and she bought Coats and Clark thread-it has a really odd texture.  It keeps birdnesting even though the tension, and needle are correct.  Could it be the thread?  Anyone had issues with this?

I have a Janome, but have the same problem with Coats and Clark.  Unfortunately, I just haven't found it to be very good thread.  (I'm also usually a Gutermann user who doesn't have the same problems with that brand.)

At the class I just went to (I have a HV Sapphire), the instructor said we should always use "100% Something" thread, and that the dual duty type is not good for the machine -- it leaves behind fuzzies that gum up the innards. 

I thought this was an interesting article on about.com:

http://sewing.about.com/library/weekly/aa102100a.htm

Thank you!  I'll pick up some trusty Gutterman.

I just used some Coats and Clark cotton coated polyester, and found the bird-nesting to occur too.  Don't know where I got the thread, but HATE it for the machine.  I'm going to stick with 100% from now on!

Not to beat a dead horse, but I have never had an issue with Gutterman - if there is a thread issue it is because I did something silly with the tension or bobbin case.