I've run across a couple problems on the jQuery code for Multiship and have corrected these in the sample code in the wiki (and updated code version to 2.2)
Issue 1: Clear out the field that holds the new name so it's fresh the next time you want to add a new recipient.
Issue 2: If you are using hmac verification, jQuery('input[name="shipto"] won't pick up the shipto field. It needs to be: jQuery('input[name^="shipto"] which means "field name starts with shipto". This seems to work better on my multiship integrations.
Issue 3: Really a sub-issue of 2, I was getting a lot of 'undefined' values set in my cookies so I trapped for that as a non-displayer along with 'null' and ''. Also, don't show divider option if there aren't any valid shipto options.
The only thing I wanted to check on with those who know better, is that I took out some jQuery('input[name$="shipto"] (which means "shipto" at end of name) in favor of the more open-ended ~="shipto" because in hmac verification, the field name won't end in "shipto" any more. If you just wanted to get the 2:shipto and 3:shipto, it could be name~=":shipto" but I'm not sure if that's really necessary.
2.2 posted. Thoughts?