Is My Job Title the Issue?

Dear Experts, Thanks for offering this service. I've been following the TAPs and found them to be really insightful. I'm hoping you can shed some light on the situation I'm facing. Even if it's just to tell me that I'm one of the many experiencing tough luck! I am only 18 months out of college. I had some extremely solid, prestigious internships and leadership experience while enrolled, mainly in communications and specifically working with nonprofits and public affairs. I spent the last year working as the Marketing Manager of a start-up company but realized that I wanted to pursue my real passion in nonprofit work. I am also currently involved with several nonprofits, so I have continued to develop these skills in unpaid positions. I know that this is a tough economy and complaints about the "black hole" resumes disappear into are legion, but I am honestly at a loss for the response I am getting (which is pretty close to zero). I have had my resume reviewed and gotten gold stars all around. Everyone who I have talked to (including recruiters, potential employers, former supervisors) has said that my Cover Letters and Resumes are excellent. I know I'm qualified for the nonprofit jobs I am applying to, which generally require 1-2 years of experience. I feel like I am following all the excellent advice I've received, but I have sent out literally hundreds of resumes over the past few months with no progress toward a paid job (or even an internship!). I've started to wonder if the title of "Manager" on my resume is putting people off when I apply for these "Assistant" and "Coordinator" positions. In my cover letters, I address the perceived step back by mentioning my eagerness to break into the nonprofit world, but I can't help but wonder if I should adjust this title as my search continues? Do you think this would help me stay out of the circular file? Would it be unethical to call myself the start-up's "Marketing Coordinator" instead? I know my former organization's president wouldn't have a problem backing up any title that would help me move forward out of this rut! Could this be the root of my problem? Is there something else that I am doing wrong? Is this just the state of job searching today & I should "keep on truckin" as I have been? Our Twitter Advice Project (T.A.P.) is no longer an active campaign. To find an answer to the above question, please use the "Search" box in the right-hand column of this website.