i don't know what the heck splunkle is talking about, so i'm not even gonna go there.
if you want different time signatures, there's two ways to do it. for a whole song, set the 'project settings' to whatever you want it at. play with it till its right.
if you want different patterns to be different amounts of beats, hurrs whatcha doo.
like splunkle said, the '--' in the top left corner of the step sequencer changes the X in X/4. now, since each pattern can be different lengths, you need to know how to put in a five-beat long block into the playlist, or however many beats it is when its not a multiple of four. by selecting the playlist and pressing 3 (or, zoom to the closest setting) and you should be able to click in the patterns into the playlist exactly how you want it to be...because instead of four-beat bars being the lines for the grid, each beat is a line. therefore, any wierd time signature will fit in.
that make sense?