W2600CR2 has two SKUs, W2600CR2 (normal SKU) and W2600CR2L (Lite SKU). The only difference is that the Lite SKU doesn't have I/O module slot, and it was only available for a limited time. Both SKUs use same BIOS package.
Your PBA# indicates your board is normal SKU. However, it seems it's an early pre-production board. What is your current BIOS version?