When I open up Windows Media Player and I browse by artist, sometimes the list will be grouped by the first letter of the artist and sometimes there will be no grouping applied at all.
It's totally inconsistent when it groups and doesn't, and sometimes it will be not grouped, I can go into an artist and when I come back out the list has been grouped.
Can anybody explain what on earth is going on, and if possible force the non grouped view all the time, it's much better.
Picture of grouped artists:

Picture of non grouped artists:

I am not switching to another media player, so don't even bother suggesting that.
Operating system is Vista SP2, for what it's worth.