BIG TIME! Thank you so much.
First of all, this will be a development post, so maybe incomprehensible for someone.
Roland F. pointed out, what is the problem:
Just one thing: drag up was not only go to inbox in the original version. go back to the inbox or the label/folder of the current mail would be better.
I know that and I would like that too. But it is impossible. My first idea was to emulate Gmail's hotkeys.
Some users are experiencing problems with triangle image (fails to load). The original documentation wrote this solution:
// Code for displaying /images/myimage.png:
var imgURL = chrome.extension.getURL("images/myimage.png");
document.getElementById("someImage").src = imgURL;
Yeah, I already know that, and I'm using since the first release. Sometimes works sometimes not. But I didn't know why! I read a lot of article, but I didn't find any useful. First time I created image loading fallback to an external image version. It doesn't work either. So I decided to drop the image and made it with CSS 3. It's coming soon with the next release.
Hold on guys!