I'm running XP with a custom visual style (http://b0se.deviantart.com/art/GUI-Relax-4544152. The multi-taskbar displays the correct background image for the overall bar, but the images for the task button are missing or wrong.

Specifically, there is no button graphic when an application is selected, and the wrong graphic is loaded on hover, selected, selected+hover. I'm not sure which graphic it's using instead of the correct one--I don't recognise it from any other elements of the skin.

I can provide a screenshot if necessary.

Sorry for the delayed reply. Here's the screenshot comparing the original taskbar skin with the second taskbar.
http://img23.imageshack.us/my.php?image=multitaskbarskinissue.png

I see you've fixed this now, very nice. Although you haven't mentioned it at http://www.binaryfortress.com/Forum/index.php?topic=796.0

To be super picky, and this is just for your own reference, for some reason the selected/active state of the taskbar button on the second taskbar is darker than what it should be.

Ah, one other issue (which you might already know about and is why you didn't mention that this bug was fixed), is that the button alert animation isn't working. I.e. when I receive an chat message, the taskbar button for the chat window doesn't blink.