In Java viewer open an existing report.
Click on Input Controls on the left side.
Observe the New button.
Change to Design mode.
Click Input controls on the left side.
Under Document Input controls it states:
"There are no input controls defined in this document. To define a new one, please click here."
Change to Reading mode.
Under Document Input controls it states:
"There are no input controls defined in this document. To define a new one, change to Design Mode."
Note the New button has now disappeared.
I observed this in BI 4.1 SP6 patch 1 but after uninstalling patch 1 due to other issues this behavior still exists.