The release JVM 1.6.0_10 introduces a new Direct3D accelerated rendering pipeline for Microsoft Windows Platforms which is in fact a fully hardware accelerated graphics pipeline based on the Microsoft Direct3D 9 API.
Unfortunately the new rendering pipeline causes a loss of rendering performance when displaying some specific grayscale documents. Using the hover lens for such specific documents you will notice the poor rendering performance.
Since the new pipeline uses hardware acceleration capabilities offered by video cards, it is very important to install the latest drivers for the cards.
If installing the latest drivers does not improve the performance, the disabling of the pipeline could be an alternative. To disable the pipeline in such cases pass the parameter -Dsun.java2d.d3d=false to the Java VM or set the J2D_D3D environment variable to false.
We are working on a solution or a workaround for this problem, but we cannot provide a jadice answer for this problem at the moment.