SSL probelm with PHP and MySQL

I have 2 php scripts. Script A contain my class file. Script B will include script A.
Script B contain only code and no interface, which will re-direct to other page using Header.
However, when I put these scripts under same SSL directory, the problem occur, is said I already have some output in script A. It never occur before I use SSL.
When I combine 2 script together, the error never occur again.
Any idea how to solve this problem because script A is important and include by other file too.

Thanks.

vic