Update Program-cannot select an item

[John R. Sowden]

I received an update this morning (daily) for 12.04.  There were three 
update for gpg and one for a pdf editor via a commercial ppa. The 
heading in bold for the ppa was checked, but the editor program was 
not.  The program would not allow me to update it.  I tried:
   click with (left, center, right) mouse button on the box
   enter while the item is selected
   space bar while the item is selected
   select the "select all" item in the drop down menu
Update still displayed "three items to download".  I went ahead and 
downloaded them.  The pdf editor was not downloaded.  It is still in my 
update screen (window was not closed).

Assistance?

John