Hi there,
If you haven't already done so you might want to look through this thread:
http://forum.giga-byte.co.uk/index.php/topic,5704.0.html where I review the GA-990FXA-UD5 as it might help answer some questions.
When it comes to running RAM above 1333MHz a lot depends on the CPU you are using. But, you will have to manually set the speed, timing and possibly voltage to run the RAM at it's rated spec's.
At the present time the 9 series chipsets actually use the same drivers as the 8 series, which is why you couldn't find any on the AMD website. The Chipset and the LAN are different components and as such use different drivers. Do you actually have a problem with any of the devices when you look in Device Manager?