double URL encoding of anchors in banner

I've setup my rotor content(banner) and in the "link URL" field I have put a named anchor, eg. mypage#section1

when I click the banner the address bar on the browser is url encoded twice to become 'mypage%2523section1'.

The %25 is the url encoding of the % symbol, so it looks like it's url encoding 'mypage%23section1'. Indeed when I hover over the banner, the status bar at bottom of my browser says 'mypage%23section1' so the act of clicking the banner must do the 2nd url encoding!?

If I actually type the url 'mypage%23section1' it shows only the main top of page, not section1 which is further down the page, so url encoding doesn't work anyway.

'mypage' is a urlalias if it helps.