Issue
If CSS is enabled in the Region/Copyright tab of the Disc Inspector for a Standard Definition project, and you convert that project into a High Definition project, the CSS setting will be stuck on, and you will be unable to switch it off for that project.
Solution
Before you convert a Standard Definition project to a High Definition project, make certain that the Format for CSS checkbox in Disc Inspector is not checked.
The Format for CSS checkbox should not be checked when converting a SD project to HD.
Even though CSS is not applicable in the context of High Definition DVD projects, unexpected results may occur if you attempt to format a project that had CSS enabled when it was converted from Standard Definition.
If you have already converted an SD project that had Format for CSS selected to an HD project, you can still format the HD project for replication if you deselect the Copyright Management checkbox, also in the Disc Inspector’s Region/Copyright tab.