Reply #1: I wouldn't say so...

[kay1864]

1) It's common for you the interviewee to be dressed up for an interview, and to be dressed better than the (business-casual) interviewer. So no--if anything you get a couple points for wearing a suit.

2) I don't know what this job is, but just b/c she's 20 years younger doesn't mean she's making 20K less. I've worked with people 10 years older and 10 years younger, but we're all making about the same. Many people come into jobs from a different field, and whether they come in at age 25 or 45, the salary range for the job is defined by the job, not age (or even experience).

3) I wouldn't worry much about omitting a 3-month job, since you have a good reason for leaving it off, and especially since you called back to correct your error.

Let us know if you get that second interview!