In Miniplayer mode, the album art is displayed incorrectly(horizontal and vertical lines). This only happen with the Vitreous skin.
Steps to reproduce:
1. Play a song
2. Switch to Miniplayer with the Vitreous skin
3. Look at the album art.
Also not sure if it's the intended behavior for Windows 7 but when in MM4 is in Miniplayer or Microplayer mode and pinned to the taskbar, it will show the button as if MM4 is not running. While in this state, clicking on the MM4 taskbar button will result in Windows trying to open another instance of MM4.