Image gets blurry during puppet warping edition

Hello,

I'm using the puppet warp to match one image on the other using a certain level of transparency.

I used it for the first time yesterday, everything was working fine.
But since the second time I used it, the image I'm editing get so blurry, that I cannot match both images, since I stop seeing the pixel.

Here the comparison:

• normal image

• after starting puppet warp editing and setting the first pin

I tried it several times, but each time I set the first pin, the image gets blurry.

When moving around, the image looks normal, the moment I stop the moving, it gets back being blurry.

Just to complete the info: I' editing images images of about 5 Gpixel. Using PS CS6

I hope someone can help me on this one

Cheers