Bootstrap site: right-hand navigation text becomes rasterized after scrolling

Created by: mg1075

In the bootstrap site (e.g., http://getbootstrap.com/javascript/), the side navigation text looks "clean" prior to scrolling:

Yet after scrolling down, the side navigation text looks rasterized.

This is on a Windows 7 machine, using Chrome 35.0.1916.153 m.

Any insight as to why this is happening?