I have determined that when the number of characters on a line in the Template Pattern exceeds 85 that the buttons on the right for Add/Remove on Variables start to get pushed out. If you use long variable names, the pattern line can easily exceed this width.Yup, I duplicated the issue here, Jeff. It seems that the text area for the snippet is sized to be as large as the longest line, and the layout used to hold the variables list sizes along with it. Unfortunately, at some point (on my machine, this happens when the dialog is wider than the screen) the layout pushes the buttons for the variable list off the right.edge of the dialog and you cannot expand the dialog enough to see them.
The problem is that window for the template is not adjustable and as they expand the body, the buttons on the right get lost. It does not matter if you extend the margins as the area for the buttons seems to be overlayed.