Acrobat 8 and Field Calculations Assistance Needed

I have created a form using live cycle designer and as a finishing touch wanted to add row calculations. The tutorial listed below seemed simple enough yet my applications didn't work the way of these instructions. Hoping someone can assist to explain what I need to do.

Basically, the tutorial tells you to open the form in professional, select field then go to properties and access the field calculations tab.

But my professional will not do this, form editing is greyed out and instead of 'Forms --- edit form in Acrobat, when I open my form inside of professional the menu item changes to 'Edit form in Designer'.

Any subsequent attempts to manipulate the form fields launches LiveCycle which does not provide that properties/field calculations tab displayed in the tutorial.

Is this a version or a bundle issue?
Do I have to modify the settings of professional to enable this functionality?
Can anyone assist?

Listing my application version and link to the tutorial below.

~Version: 8.1.3 Adobe Professional/LiveCycle bundled from purchasing Adobe Web Premium CS3.

~Tutorial: http://www.acrobatusers.com/articles/2006/09/nuts_bolts_forms/index.php