it happened every day, every where, to...

every one...even if a company has a job code (grade level) system.

my suggestions:
1) never trying to know others' salary in your company;
2) never disclose other's to any one;
3) never compare other's with yours;
4) never trun yourself down because of his $ > yours;
5) never take my suggestion if you have done 1) to 4) above.