Tell us which bios version you have right now.
From the main bios screen, press F9 for the bios information.
The Q8300 is NOT in the cpu support list for your motherboard:
GIGABYTE TECHNOLOGY Socket 775 - NVIDIA nForce 680i SLI MCP - GA-N680SLI-DQ6 (rev. 2.0) CPU Support List
There are only a few quad core processors that are supported.
It might be worthwhile to contact Gigabyte tech support directly to see if they already have an unreleased special bios version that will support your Q8300.
The F5g beta bios is only for the rev: 1.0 motherboard, not your rev: 2.0 board.
What specifically are your motherboards "silly buggers?"