Dating yourself with incomplete resumes

Apparently, there's been an increase in job seekers sending potential employers incomplete resumes as they try to break back into the market. By choosing to omit college graduation dates and even the years during which they worked in previous jobs, some people believe these job seekers are being deceptive - either on purpose or by accident - and they're simply pitching their resumes, further extending the job seeker's time on the unemployment line in many cases.

Have you run across this issue at your firm? How do you handle it?