I just installed 6u2 on two separate machines, one Vista, one XP. Both using LCD monitors and NVidia cards.
Please have a look at the attached screen capture. Notice the artifacts (indicated with green arrows) that I saw on the Java image in the dialog.
You can view the source graphics in the UE spec: http://xdesign.sfbay/projects/java/j2se/consumer/Install/j1_installer.html, and they look fine (Vista laptop, Intel graphics chip).
After overlaying the original on a screen capture in Photoshop, it appears that the artifacts are the result of the graphic being shrunk by the installer -- 2 pixels in both the vertical and horizonal axes.
UE is going to trim the masthead and the welcome dialog images by 1px. Then we'll drop them in the ws. We'll also need to add 2px to the h/w of the JavaAd. Also, as part of this error, we'll make sure the font in the first and last dialogs match.