Placed linked Illustrator file not updating or relfecting saved changes in photoshop

Hi,

I am currently working on some illustrator graphics which I placed in a Photoshop mock-up of our website in order to see how the elements look on the site as I develop them. However the placed, linked illustrator document within Photoshop will not show any changes after I save the file in illustrator.  Even if I right click on the linked layer in Photoshop and select "update modified content" it still makes no difference.

The only way to get Photoshop to reflect the changed illustrator artwork is to literally place it in again on a new layer.

Whats going on here? this isnt how links work in illustrator or indesign.