PDN now does this wierd thing when I flatten/merge layers. Say if I merge a layer down, and it's set to additive or whatever, then when I merge it down it flickers to as if it is set to normal, then goes to what it should look like when merged. It's only really a problem when I'm trying to compare what a layer looks like visible/not visible. This also happens when I make a layer visible/invisible.
If your not understanding what I'm saying, I could try to upload a video. Also, This happened when I was on XP, then upgraded to win7, and is still happening, so not OS related.