There’s a NY Times blog post about whether you should lie about your salary when applying for jobs.
My answer is that you should make up a salary that slightly lower than the salary you would like to be offered. No one can verify this information because companies keep their salary information secret. If you call up your HR department and ask to “verify” the salary of a recently departed coworker, I doubt that you will find out what his salary was.
The corporation hiring you is probably lying to you about something (because you're just one of the small people), so it’s not unethical to lie to them.