As for why my H1 starting date is different with my wife's H4, I have no idea.
-H4 status start date normally is the date of I-539 approval and that is why her H4 start date on the I-539 approval notice was different from your H1 effective date (this was a mistake becasue the USCIS officer did not check/cpmpare both H1 and H4 cases carefully), but it does not mean her H4 was effective before your H1 effective date. Techincally, her H4 was effective on the same date as your H1 was effective-Oct.1, 2005. So, don't worry about it.
