Scroll inside fixed div

I have a fixed div – it takes up full height, and the left half of the browser.

I’m using overflow:scroll to allow users to scroll up and down the div.

Inside the div, I have anchor links, as well as the divs which the links are anchored to. When I’m not using the plugin, the links jump to the right place in the div. But when the plugin is active, there is no scroll or jump.

The plugin does work perfectly if the links/locations are in the main body of the page. Is there any way to make this work within a fixed div? Any advice is appreciated.