Two things that might help you clarify it in your mind:
1) The period of the sine function is 2pi. Results will ALWAYS be grouped in some way so that infintely many solutions will be exactly 2pi apart. There may be more than one group.
2) There are other symmetric relationships that must be kept in mind. One such is sin(x) = sin(pi - x). Results related in this way will NOT differ by 2pi.