Address block in Goldmine letter won't retain single line spacing

I created a letter template in Microsoft Word and added it to Document Center in Goldmine. The address block appears to be in either 1.5 line spacing or double spacing and I need it to be in single line spacing. I have opened the letter template and edited it, formatting the address block to single line spacing, but after saving the template, when I view it in Goldmine or reopen the template file in Microsoft Word, the formatting goes back to how it was (not single line spacing).