This requires being a subscriber to ISTECH and having loaded an Update.  Next time you print a packing slip (SO-C) you need to answer the following questions.  The second question, which is around halfway, is "Print Notes?" which should be answered N also the same with the next question about hidden notes.  The sixth question is "Print Options ?", when this is highlighted there will be in the lower right hand corner the opition to save the settings.  You save the settings with the No to the printing and that becomes the default and no notes should be printed.
 
 
R Hitch