I came up with a theory for how this problem could occur.
The Cardas plug has a different shape from the other cable. Either the ridged portion of the tip section of the plug is wider than the other plug, or it sits further up the plug than the other one. The Cardas plug then stretched out the jack, so it no longer can make proper contact. The easiest solution to this problem would be to use the Cardas cable. The other solution would be to bend the contact on the jack back into shape. It may get bent back out of shape if you continue using both cables, or perhaps the contact was overall marginal on the Cardas cable and by reshaping it, you will improve performance on both.
This may or may not be the cause of the problem, but it is the only explanation I can come up with that matches the facts presented.