Hi,
I was wondering when someone notices 😉.
You are right, some Windows 7 cursors have 2 sizes in them. The standard 32x32 version is used in 96 and 120 DPI modes. Windows 7 uses the 48x48 version when it is set to 144 DPI or more. This is still very rare.
The latest version of the cursor editor was released right before Win7, in the era of single-sized cursors, and I decided to hide from users the fact that a cursors actually may have more images in it. It confuses 99% of users.
So, the cursors with multiple sizes are supported internally, but the user interface hides that. I believe you can re-save the cursor, but you cannot easily access some parts of it and some operations may delete one of the images.
Until a new version is available there is a partial solution. Because the user interface is the most limiting factor and because it is configurable, there is a way to allow you to work with both of the image. You need a modified layout. So, if you want partial support for Win7 cursor, download and unzip this layout: rsrc/cursor-editor-layout-win7.zip. Then go to Application options and check the "Show menu commands for...." checkbox. Then Go to menu "Tools"->"Manage layouts". Delete the layout named "[0409]Cursor Editor...." and import the one from the downloaded file. Once you do it and open or create a cursor, you'll have an "Images" panel available in the right pane. It will allow you to add/delete images from a frame of a cursor.