The braided wire used now is heavy duty and will carry more current. Braided wire is known to be more resistant against rf noise. It was not used to fix a problem.
Yes there is a known problem with the earlier digital servos that Hitec has stated.
http://www.hitecrcd.com/Support/servostatement.htm
However, if the servos are reset with the HFP-10 programmer V1.03 or later they will have the same software as the latest version. Be aware you should not reset the servos through an extension... this may have been the cause of WreckRman2's problem since the servo he has in question was reset through an extension. The longer leads may cause a problem when programming. Thus, you should always connect directly to the servo when resetting or programming it.
Hitec stands behind our products 110% and will do anything and everything in our power to solve a problem and take care of our customers. There is no "known" issue other than the one I posted a link to. To my knowledge none of the components have changed in those servos except for the wire, anodizing on the output shaft and labels.
Mike Mayberry
Hitec RCD USA Inc.