Ok, I updated BIOS to F11 again, this time using QFlash, but the audio still is not working. I also reinstalled the audio drivers after cleaning them out thoroughly.
Windows device manager is also now showing an unknown device under sound controllers. Both the Realtek and eCLARO soundcard drivers are installed. I've tried using the automatic driver updater for the unknown device, but Windows reports that no driver can be found. There's also other sound devices, which have always been there - they're from my nVidia GTX 460 graphics cards. I've tried disabling them before, but there was still no sound from Realtek nor the eCLARO card.
It seems like the audio devices aren't properly being recognized. Is there something wrong with the chipset in relaying audio data in F11? The version description says it supports "Dolby Home Theater PCEEv4", but I'm not even using that.
Update Edit: I have resolved this issue through a repair installation of Windows 7. Thanks for the assistance.