Thank you for your comments and vote borcky and Gemini22. Your feedback has been passed on to our product development team for consideration.
Gemini22 - I've posted a detailed response to your post on how to deal with these part payments. -
http://community.myob.com/t5/MYOB-Essentials-Accounting/Matching-part-payments-to-invoices/m-p/267851/highlight/false#M5118
Regards,
Suja
MYOB Support