Combined post issue

Hi Fellow sellers!


I am having issues with combined post:


1) not letting me know when it is applicable


2) not issuing a postage price to the buyer when I recalculate using one of my postage options


The choices are:


Standard postage


Registered postage


I select one add an additional postage fee (.50 cents) instead of another postage fee, the buyer only gets charged  the  .50 cents


Has anyone had this issue?


How to fix???


Cheers


Neil