If you're using FM14, name the portal object, then add a "Refresh Portal" step to the script. That will force a refresh of what the portal is displaying.
Try adding "Go To Field" and specify the first field in your portal (or go to object), immediately after the Go to Portal Row step.
I think you're going to the row, but not going to any object/field on the row to "activate" it in the view.
In general, if your portal has more records than the number of rows you specify, you will need to have the vertical scroll bar to access the extra records. I believe you can use portal filtering to display a specific set of records to accomplish what you want.
I'm guessing Mike's right about nothing actually "happening" when you just go to the next portal row. His method should work to bring the proper row into view. rgordon brings up another good point, but more from a user experience point of view.
Imagine there are 40 records. With a vertical scroll bar, the user could simply scroll through the records and get to the 38th one in a second or two. Using buttons to simply go through rows will result in 1) the user clicking a lot of times to get where he wants and 2) the user wondering why you make him click a lot of times when he could simply scroll and click where he wants.
There are good reasons to loop through portal rows one at a time. But you may want to rethink using single click buttons to navigate to areas which are more quickly navigated to with the mouse or the scroll bar.
Looks to me that you're trying to reinvent the wheel.
Anyway, if you don't want the scroll bar to be seen but you need it, just slap a white rectangle over it and call it a day.
Thank each of you for your help. I actually went a different direction.
Again, thank you all!