Professional sound on A7N8X-E - enable Delay Transaction?

A friend of mine has problems with recording music on his computer. He'sgot an M-Audio Audiophile 2496 professional sound card and gets pops/clicks when recording through the MIDI interface. After getting sick of the problems he decided to replace his VIA-based EPoX mobo with the best and bought an Asus A7N8X-E mobo instead. It helped some, but the clicks are still there. I've tried to help him by fiddling with BIOS settings; changes in the memory settings gave the most results, but the clicks never disappear completely. Other owners of M-Audio sound cards have experienced the same problems and here is a fellow who seems to have solved it:
http://pub136.ezboard.com/fdelta1010forumthedelta1010withotherhardware.showMessage?topicID=361.topic

He says that by enabling Delay Transaction on his mobo, the clicks disappear (enabling/disabling PCI Delay Transaction makes no difference). He used wpcredit/wpset to set Delay Transaction on his mobo, since only PCIDelay Transaction was available in his BIOS setup. I've flashed the mobo with the latest Über BIOS, but that doesn't make available any of the Delay Transacion settings and I have no idea which PCI register bit toset in wpcredit to enable Delay Transacion on my friend's nForce mobo.

Any suggestions?

/Martin