Hi Lynette,
In addition to checking the customer details to make sure first name and last name are entered, you also need to go into your preferences, edit drop down menu > preferences > Send forms > company preferences > change the drop down statements > check the 2 fields for to/dear and first/etc. to see what is selected.
I hope this helps.
Kind regards,
Sally McIntosh (sally@samsolutions.com.au)