Block not updating

Hi all,

I'm using a block saved in a dwg as a frame for my drawings. I've updated this frame so it will make it easier applying to all my drawings. However, when I insert block (n the drawing files), it inserts the old block (my block was an advancement/edit of a previous block).

I don't know why this is happening. The attached dwg is my new block (that shows as the old block). Below is a photo of what appears in my file.

Thank you for your help.

Toby