Help with faulty IDT Audio Codec

[Seth004]

Motherboard: Intel BOXDX38BT LGA 775 Intel X38 ATX DDR3
AA Revision: D85848-503
CPU: Intel Core 2 Quad Q6600 Kentsfield 2.4GHz 2 x 4MB L2 Cache LGA 775 Quad-Core Processor - OEM
Memory: G.SKILL 2GB (2 x 1GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10600) Dual Channel Kit Desktop Memory
Hi, This is an ongoing issue with my DX38BT. Intel have replaced the motherboard once but the problem remains. Any help will be appreciated.


Video Card: Geforce 8800GT 512MB
P/S: Antec Truepower Quattro 850W (TPQ-850)
OS: Windows XP Professional SP2
BIOS: BTX3810J.86A.1251.2007.1016.1510
Audio: Audio: IDT* 92XX Driver 5790_5713_v83

Issue: Onboard IDT Audio Codec not recognised in hardware after prolonged power-down.
Scenario 1: Soft reset: Audio Codec recognised on restart, sound OK
Scenario 2: Power down < 15mins: Audio Codec recognised on restart, sound OK
Scenario 3: Power down > 1hr: No Audio Codec recognised on restart, no sound
Re-loading the IDT drivers fail as the hardware is not recognised.
The only way to restore the codec is to flash the bios.
After restoring the codec sound OK, but the above cycle repeats.

[Seth004]

PS
After some more testing found that the codec only fails to load from from state G2 (No fans but standby led on motherboard is on) and only after 15 minutes of being in that state.
If I physically disconnect the power cord and wait till the standby led dims, the codec will load on re-boot.
Codec loads OK from G1/S1 and G1/S3