When I was just getting started in the Recruiting business, a very successful recruiter told me that one of his red flags was a typographical or grammatical error in a resume. His point was that a resume is the most important document a person uses to "sell" his/her skills, and he/she should make darn sure that there are no errors
. My mentor told me that a lack of attention to detail on something as important as a resume often indicates an overall lack of attention to detail on the job.
Read more here