Yup, like Stu said, something on the peripheral bus is pulling down (to zero) D5 (the sixth data line). So it is unlikely to be a header problem, and much more likely to be a damaged ethernet chip. The CS4231A is probably just fine, and is likely to show up as working again once the ethernet problem has been addressed.

As Stu said, the BIG option is to have the chip replaced. The quick option is to have someone just lift the D5 pin of the ethernet chip, so that it no longer shorts out the peripheral bus. No ethernet that way, but everything else ought to work.

Cheers