If you are running the latest version of the Editor (3787 - which you should be), you may notice that the select cursor and items with no face (like timers and connection sensors) now display as squares instead of isometric (diamond-shaped, like the map squares).

If you have this problem there is a simple fix:

Go to the folder where your Editor is, and go down to the resource\system folder. You should see some png files starting with 'i', and files with the same name without the 'i'. (Not all 'i' files have a corresponding non-i file).

To fix the editor:
1. Delete these 4 files: noarch.png, noface.png, seltile.png, unknown.png.
2. Rename these 4 files, taking the 'i' off the front: inoarch.png, inoface.png, iseltile.png, iunknown.png

Restart the editor and the problem is fixed.

Thanks Grommit - that one was bugging me.  What about gridtile.png ... there is an 'i' and a 'no-i' version of that one as well?

That as well. I left that out to see if anyone would notice

PS: This was a joint effort between Ragnor, Smacky and me. Linux users don't have the problem, and it wasn't until I posted screenshots that Ragnor realised it was due to a change he made to the code (renaming the png files).