Windows Media Player 12 + Tag Editor Plus

Hi...I'm a newbie on Win7 64-bit and Windows Media Player 12.
Previously, on my XP computer running WMP11, I used 'Advanced Tag Editor' to edit tags on MP3's. To do this, you simply opened WMP11 in Library View>Now Playing>Advanced Tag Editor. No problem.
With typical MS stupidity, WMP12 does not contain 'Advanced Tag Editor' by default.
To get a Win 7 editor, 'Tag Editor Plus', you have to download the Windows Media Player Plus! plug-in from some kind soul who obviously saw the need for one, unlike MS!
I've done this so here's my problem:
When I introduce a new MP3 track into WMP12 it appears in the far right pane only.
Right-clicking this does NOT offer Tag Editor Plus in the options.
However, with the tracks loaded by default into WMP12 (the Playlist 'Party Shuffle') these tracks appear in the main pane and right-clicking them in this pane DOES offer Tag Editor Plus, which by the way is almost identical to Advanced Tag Editor.

So why doesn't an MP3 automatically appear in the main pane and not just in the right pane, thereby offering me Tag Editor Plus?
This was the case in WMP11: Library view>Now Playing>track appears in main pane AND right pane.

Why doesn't WMP12 do the same?

Surely I don't have to 'Create a New Playlist' each time I insert a new MP3 track for editing?
That seems ridiculous since in WMP11 as above it was easy to access Advanced Editor and add or change any information with ease.

Clearly there's something wrong here and I just can't see where it is or I'm missing something basic in using WMP12.
I really need this Tag option (particularly adding a CD album pic to go with each MP3) so:
1) Can anyone suggest where I'm going wrong?
2) As a last resort: could I return to WMP11 assuming it's compatible with Windows 7 64-bit?
3) Would I therefore have to unintall WMP12 first and is this advisable?
Many thanks