Problems with F8 BIOS for GA-Z87X-OC?

[Mari0]

I updated my Gigabyte Z87X-OC BIOS to F8 and now I cannot boot Mavericks from USB. Tried 3 different USBs in all the possible USB ports with the same bad result. The message is "Reboot and Select proper boot device or Insert Boot Media in selected Boot device and press any key".
What is strange, Windows is booting from USB.
Are any settings in BIOS which can generate this problem? Any other ideas?

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Late edit
Please have a look of the partitions on the USB disk:

2 partitions on the USB disk. This could be the problem?

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One more edit

Yes, the problem appear due to the second partition. I found with google a raw image of a 8GB USB stick with Mavericks 10.9.2 and that solved the booting problem. Seems that during boot up, PC is seeing only the EFI partition.

 

[Vectriixx]

I updated my Gigabyte Z87X-OC BIOS to F8 and now I cannot boot Mavericks from USB. Tried 3 different USBs in all the possible USB ports with the same bad result. The message is "Reboot and Select proper boot device or Insert Boot Media in selected Boot device and press any key".
What is strange, Windows is booting from USB.
Are any settings in BIOS which can generate this problem? Any other ideas?

=======================

Late edit
Please have a look of the partitions on the USB disk:
View attachment 90987
2 partitions on the USB disk. This could be the problem?

=======================

One more edit

Yes, the problem appear due to the second partition. I found with google a raw image of a 8GB USB stick with Mavericks 10.9.2 and that solved the booting problem. Seems that during boot up, PC is seeing only the EFI partition.

I couldn't find a way to message you on this site so I thought I would find a thread - I am basically going for a similar build to you (the same GTX 780 graphics card and also the same motherboard just a different processor) and I was wondering if you could tell me if there are any problems that I should be aware of before I build? It would be great if you could add me on Skype or something so we could talk?