ASUS P8Z68-V PRO can't update BIOS?

Hey guys, I just recently purchased a ASUS P8Z68-V Pro motherboard. I was looking to overclock my i7 2700k, but unfortunately my motherboard doesn't have AI tweaker. It has the AI tweak feature in the UEFI BIOS but it only has where I can set my target CPU frequency like 4.3,4.5,4.7 but no manual mode or anything of that sort. I have went to ASUS's website many times trying to get the BIOS to update and every time I download the latest BIOS, copy it to a FAT32 thumb drive and try to update the BIOS with the EZ Flash utility it says "Image Integrity Check Failed". My only reason for wanting to update the BIOS is to get my overclocking options. I have no idea why there isn't a manual option. My current BIOS is 3508 and the latest I see on the ASUS website is 3603.Hopefully someone here can help me before I go calling ASUS and having to possible spend multiple hours talking to them. Thanks to all who help. I will check back in a few hours after I get off of work. If you need a full run down of my specs, they are Core i7 2700k, 16GB Crucial 1333Mhz RAM, 120GB Mushkin SSD, 1TB Samsung HDD, ASUS P8Z68-V PRO, 1000Watt CoolerMaster PSU.