During an interview for an office job without contact to clients they told me I should do something about my hair because they are a conservative, family owned company and wanted to represent this.
I simply had long, clean hair in a pony tail. I walked out of there, didn't want that job and am proud of that.
Production error nightmares, PEN. Seriously, sometimes, after working on a problem for a long time, even if rigorous testing in multiple testing environments by different people was involved, these still happen.