I think i can add a little more detail to this discussion.
I run Windows 7 Home Premium 64bit on my personal productivity machine with dual monitors. I like to keep my taskbar located at the top of my 1st desktop display (personal preference). When I have iTunes running on this display I encounter a bug when I try and maximize the iTunes application window. The menu bar, minimize, maximize and close buttons become hidden by my taskbar. Also the play controls, volume slider, layout buttons, search box, and media info display get chopped in half by my taskbar. If I set my taskbar to auto hide this bug is mitigated, however I dont like auto hiding my taskbar. I also noticed the bottom of the maximized iTunes application window doesn't meet with the bottom of my display. Instead theirs a gab between the bottom of my display and the bottom of the application window which is the same size as my taskbar. On my second display, which has no taskbar, I can maximize the application window to full screen with out issue. However when I minimize the application and then restore the application I get another gap at the bottom of the second display. Again the gap is the size of a taskbar.
Their seems to be no issue when you have the taskbar at the bottom of your main display. However I still experience the gap at the bottom of my second desplay when I minimize and restore the application.
On this machine I was also able to recreate all these issues on multiple VM instances running different versions of windows. (XP Home SP3, XP Pro SP3, XP Media Center Edition 2005 version, all variations of Vista 32bit and 64bit, all variations of Windows 7 32bit and 64bit) Note: iTunes does not support the 64-bit edition of Windows XP so i couldnt test this OS.
I was also able to test this issue on my gamming machine which uses the AMD eyefinity setup, consisting of 3 24" monitors. This setup also has the same maximize issues as discribed above. Seperate from these issues is a bug within iTunes or AMD drivers that crashes the application everytime I playback a video podcast. Havn't had the time to diagnose this bug.
Just as a side note, I also tested these issues on multiple work laptops and was able to recreate every issue no matter what the make/model or which windows OS version was installed.
Hope this information was helpful.