Have you ever "tweaked" a job title on your resume to make it look better, or because it didn't seem to "fit" exactly what your responsibilities were? It is a known fact to many hiring agents that many applicants tend to do this - or at least some form of "creating job title engineering" in order to get what they feel they deserve. The fear of being caught is often diminished by time - the longer ago the applicant held the job, the less inhibited he or she might feel to keep to the facts. Often, it is an attempt by the applicant to create a more accurate picture of the work they did while in that particular position.
No matter how long ago the job was held or how much more accurate the alleged job title may seem, hiring managers and employment verification deems this practice as lying.
More and more, prospective employers contact your former employers questioning the facts you stated - your tenure at the company, your role, your salary - everything is up for scrutiny.
You can't assume that anyone at your former company will agree that your job title could be modified - also, depending on how long ago you were employed there, the staff may have completely changed. They will be reviewing your past employment records to provide the hiring agent with the correct information and if the job titles differ, no one will understand why.
Anything different that what is in the your employment record is a red flag and can lose you a job offer. Instead of adjusting your job title, make sure your resume addresses your job function. Also, if you received a promotion during your time with the company, list all job titles held.
Being honest when developing your resume means you will have nothing to explain or defend during an interview. You don't want to jeapordize a job opportunity with a mistake (intentional or otherwise) and have to start at the beginning of another application cyle. Be honest, and never assume anything anybody will "understand."