It can be frustrating especially when there is no follow up information. The headhunters recommend placing a follow-up call within 2 weeks of sending your information to human resources or whomever you sent the resume to, to confirm that they received it. Especially if it was send electronically, as there can be glitches, so to definitely follow-up.

I don't know if you've already found these or not, but there is a good book series: "Knock 'Em Dead" that has information on how to place those follow-up calls after sending a resume and after interviewing; the series includes information on writing resumes and cover letters so your resume gets read, and interviewing, etc. It is to take an active approach as persistence pays off and shows you are interested, attentive, and on top of things.

Hang in there and keep persisting. Something will come up. Good luck!