It's not the red tab. It's the bond between the white backing and the adhesive that's causing the problem. When I tried to peel the white backing off, it takes the adhesive along with it. I had to detach it with my finger nail, already risking a weaker bond between the screen and the adhesive. I thought the problem was only around the edge of the strip (where I had to pull the red tab), but the whole strip was pulling the adhesive off the clear backing as I was aligning it with the iMac. This is the second time this has happened with these strips. And now I'm concerned, since the adhesive is now slightly compressed and there's a little air gap in the middle now...