I am a Macola consultant and have been for 5 years and I am certified in the software in Accounting, Distribution and Manufacturing Planning and Control.
I am assumming you are using version 7.5/7.6 of Macola.
I have no idea what a shipping node is, or where you update it. Againm if you post your EXACT error message and teh menu option(s) you used to ge the message, I am sure I can help.
You must own the advanced distribution module to run confirm shipping. Take a look at the regist70.txt file in your Macola root directory and make sure that advanced distribution is included in that list.
Secondly, to change from Confirm Bill to Confirm Ship, you need to delete all open orders, switch the Update IM flag in OE Setup to Confirm Ship, and re-enter the orders. This information is captured with the order, so that is why you must do this. The error you should be getting if this is the case is "Active orders on file, change not allowed".
Hopefully this helps, please feel free to call or email if you need more information. Software Support for Macola, Crystal Reports and Goldmine
dgilsdorf@mchsi.com