In some case, it saves you from having to use the buttons to scroll the tabs since you can just click on the part of the tab you can see. If you switch between the default skin and mine, you'll notice that you can see more tabs on mine. So I thought about it and as we have to deal with those buttons and the space on their right can be reduced, my purpose was to save space for tabs and avoid them being cut or hidden.
Unfortunately, the scroll wheel can't work on tabs. I don't know if its possible with POT, but if you could make the scroll wheel move those tabs the same as firefox works than that would be ideal. Let me know if you understand what I am trying to say. If you compare your skin to the new current default skin you can see the difference. Your skins are great! The only issue I have is the 2 buttons on the playlist that navigate (scroll) different playlists (top right) are too small.
