Unity 5.4.1f1 - Broken UI mask and text overflow

Hi all,

I just updated unity to the latest version (5.4.1f1) because it fixed a VR bug that was causing me an issue. This update has annoyingly broken the use of UI masks.

I currently have a UI text game object (GO) that is full of text and has horizontal overflow set to overflow. On this GO there is a mask component that is meant to only display what is within the text GO, but it doesn't it displays all the overflow text.

I've used this on a leader board list to fill the gap between player name and their score with a line of dots.

The attached image should hopefully make things a bit clearer.

Any help would be much appreciated. Thanks