Well.... I'll try to answer you ... my english is not that well .. :)

Each signature has one booelan variable, to indicate if the control will be printed or not.

The detail band over its processing, so the report starts to print the footer of the band down the detail.
Following the order, prints the signature 1 (allways printed), prints the signature 2 (user selected). But the user doesn't selected the signature 3, 4, and so on...
When the signature 2 is printed close to the end of the page, the report starts a new one, with the page header. But, the "print when" works, and nothing is printed on the "new page".