You should be able to make the Portal itself invisible by the fill and line palettes in the status bar on the left in Layout Mode. Making the background the same as your layout using the Fill Colour palette, and changing the Line Width to "None", or the same colour as your background.
I hope this helps.
Yeaaaaaa. I never realized (newbie! :-)) that you could turn off the lines like that.
I am working with a similar problem, but I would prefer not to make the Portal rows transparent/invisible, since our format employs the alternate background fill striping method. Is there a way to actually hide these empty rows (mine always appear at the bottom as well) or do I just need to break from our usual format?
The only way I can think to do this with alternate backgrounds is to use conditional formatting and a summary field in the child table.
So start with creating a summary field in the child record, I am going to call it sumCount and it needs to be set to be a Summary field and in the 'Option for Summary Field' dialog you need to specify the ParentID field that you ise as the key, adn choose 'Count of' from the options on the left and also tick the option for 'Running count'.
Now you need to apply some layout tricks to the portal to have the field you are displaying, or a text object in the background, to have a conditional format applied to give you an alternating background effect.
For the above if your portal is just displaying a single field from the child record then you can do this with a field, otherwise a good trick is to select your text object tool and click onto the layout and input a single space with the space bar and then resize the blank text area as described above.
Now give the object a border to match your current style for the portal.
Now you can apply the conditional formatting to the field/object, go 'Format > Conditional...' and when the dialog appears click 'Add' and for the 'Condition' options specify 'Formula is' and input the following
Mod ( CHILD TABLE::sumCount ; 2 )
Then specify the 'Fill Colour' you require for the fill of all your odd portal rows. then click 'OK'
Now place the field/object over the portal and position it so it is 1 pixel to the right and 1 pixel down from the top left of the portal, this will position the bottom of the field/object outside of the portal row by 1 pixel but this what you want.
Now make the portal invisible as described in my original portal and go into browse mode.
This should now give you the appearance of a list of related record with an alternate background colour that is only as long as the content.
I hope I have explained this well enough, but if I am unclear about anything then let me know an I will clarify.