this fixes most of the issues reported above
http://www.mediafire.com/download/68ia4i13dy6oa0o/MusicBeeDemo.zip
unzip into the folder where MB is installed and run MusicBee3.exe
White stripes due to subheader confirmed fixed.
Issue with iTunes Compilation confirmed fixed.
Haven't observed any more problems with those lists, but that one's harder to say definitively.
There are still issues with making selections in Album & Tracks view. Depending on where you click on the artwork, it might select all tracks, a specific subgroup, or no tracks. Unselecting doesn't always work as expected, either. I think this is also related to the subgrouping headers. GIF here:
http://i.imgur.com/qBlrCVF.gifThis is an issue that also exists in 2.5, but it came up again while testing: I have an auto-organize exception with the rule Album Track Count = 1, but it often (maybe always, hard to be sure) doesn't get applied when tracks are first moved into the library. If I open the auto-organize screen after adding an assortment of new tracks, there are almost always a handful of the Album Track Count = 1 tracks that were organized according to the main template and need to be fixed. (Maybe related: when is album track count updated? Because when I make a change to the album artist for a track, Album Track Count becomes 0, and refreshing/rescanning does not update it. So far the only way I can find to force it to update is to restart MB.)
Edit: This was happening in the previous version, too. Every time I think I've figured it out, the exact cause eludes me. My mouse wheel often stops working after I make an edit in the tag editor. Here's another GIF:
http://i.imgur.com/zVKYUng.gif...and because I'm using the Tag Inspector as a workaround, I discovered that not all tags are available when you try to add a new tag. Specifically, I tried to add Sort Album Artist and it gave me TXXX/SORT ALBUM ARTIST instead of TSO2. None of the Sort tags show up in the drop-menu in Tag Inspector.
A final related observation: I use a virtual tag for sorting & grouping in album & tracks view, which uses Sort Album Artist if there's a manual value entered. If I remove the manual Sort Album Artist from a track, instead of substituting Album Artist or another value based on the virtual tag it just says Unknown Sort Album Artist until I restart MB (maybe the same problem as Album Track Count?).