Thank you for your post.
Yes, the data should display the same on both Mac OS X 10.4.x, 10.5.x and 10.6.x. However, it is possible you have a corrupt font. That would definitely account for data not appearing on a layout. What font are you using to display the Invoice? On your MacBook (Snow Leopard), if you change the invoice fields to display a different font, does it then display properly?