I have a problem with the plugin, I use this :
add_image_size( "work", 520, 340, true );
I upload image then i change value of width like that:
add_image_size( "work", 529, 340, true );
I start Force Regenerate Thumbnail on the image in medias menus. All thumbnails are regenerated but the thumbnail - 520x340 wasn't deleted!
Your plugin do normaly that, right? That the difference with the regular Regenerate Thumbnail?