I have also seen studies - and I'm sorry, I don't keep a cache of links - saying that static stretching of cold muscles makes them more prone to microtears.
Here's a google search page:
https://www.google.com/search?q=stre...hrome&ie=UTF-8
Personally cold stretching never did improve my on the mat experience, while general movement, range of motion, rocking into rolling, and tai sabaki do.
Hey, I know it's a minority view and I know most of the folks in my dojo are hooked on long static stretching before training.