I'm working with EPImage for CMS 7 taken from https://github.com/tuanvt/EPiImage-7.1 (via the comments on this thread: http://world.episerver.com/Blogs/Alexander-Haneng/Dates/2013/1/EPiImage-and-EPiServer-7/).

A single image property works fine e.g.

[Display(
    GroupName = SystemTabNames.Content,
    Order = 20)]
[UIHint(Constants.EPiImageUiHint)]
[BackingType(typeof(EPiImageProperty))]
public virtual EPiImagePropertyData Image { get; set; }

But the image gallery isn't working. The property on my PageType never gets assigned a value. Editing works, and the value is being persisted in the database (I've confirmed this by inspecting the database manually, as well as the correct data being presented in the editor UI after a refresh).

I've added the code below to try and catch the call to the setter but it never gets hit.

 private EPiImageGalleryImageCollection _images;

[Display(
    GroupName = SystemTabNames.Content,
    Order = 20)]
[UIHint(Constants.EPiImageGalleryUiHint)]
[BackingType(typeof (EPiImageGalleryProperty))]
public virtual EPiImageGalleryImageCollection Images
{
    get
    {
        if (Debugger.IsAttached)
            Debugger.Break();
        return _images;
    }
    set
    {
        if (Debugger.IsAttached)
            Debugger.Break();
        _images = value;
    }
}

So what part of EPiServer is deciding not to bind a value to the Images propert?