I owned a stock that had an ex dividend date of 8/10/12. I had sold a covered call which was well in the money so I expected to see the call exercised on 8/9/12. The call was not exercised 8/9 but when I opened my brokerage account on 8/10/12, it had exercised on that date.

Per my understanding, since the option was not exercised until 8/10 which is the ex-dividend date, I should get the dividend. Am I correct and if not where I am going wrong.

Yes, I believe you are correct as long as the stock was still in your account as of the close of trading on August 9. In the US the ex-dividend date is the first date for which the buyer can not expect to receive the dividend, so whoever owns the stock as of the close of trading the day prior to the ex-dividend date receives the dividend. The rules are a bit different in other countries.

To make sure you can check the web site for the company - in their investor relations page they should state whether the dividend is payable to stock holders of record as of August 9.

Yeah, that's right. Be sure to check our TOS and your paid advisor.