Extron Electronics Manager Position interview questions

I've interviewed three times up there. Sadly I have never seen anyone smile over there. I have met two managers, three directors, a VP (Not HR VP) and a HR manager. Everyone thinks I am OK, so they have prepared the offer letter and then submitted to their HR. I have waited for 3 days and then been told they have changed their mind because the HR VP did not sign the offer letter..I am a very honest person and do not have any criminal record. So, why did he/she not sign the letter? Well, I do not know.