hey guys I'm new here, so I wanted to chime in a bit... anyways
for me writers block doesn't happen that often because if something isn't working I immediately drop it and start something else. Making music, writing something, whatever it is, it doesn't make any sense to bang your head against the wall.
One thing that really helps if I find myself in a particularly bad drought is to disengage myself completely from anything creative. I usually will pick up a new game and roll through it or actually remove my butt from the computer chair and exercise religiously (for a week and then go back to sittin on my butt)
the point is if you're not coming up with anything, thinking about why won't help, you've got to live your life and take the inspiration as it comes, if that makes any sense