Can't update bios with m2n-sli deluxe motherboard

I am having problems updating my bios in my motherboard. I have downloaded the bios from the asus website (version 603) and I have tried updating them using both the awardBIOS flash utility and the ASUS EZ Flash 2 utility. The ez flash 2 utility gives me an error saying the file size is different then my current bios and the awardBIOS flash utility says "the program file's part number does not match with your system!" I have used both the DOS and "other" version of the bios from the asus website and still no luck. I have absolutely no clue what to do Sad. Any help would be greatly appreciated.

agreed with the last post. I have an ASUS K8N-E Deluxe and I was always trying to keep the bios up-to-date. However, I've found it that it's not necessary if your current bios works fine and allows you to do whatever you need it to do. On a side note, ASUS's bios updates are not always adequate and sometimes is best to stay with what you have, especially if you don't have any issues.