Made form and set font, previews fine but prints out in different font? Eek! Thx

Hi there,

I realise this is probably a stupid question and maybe something to do with embedding fonts or not (which I don't know how to do either) but I don't understand when it allows me to set it in the options, and it previews fine when I type things in, why it then prints out with Helvetica or something. The font is Sunday - a free font, so not sure why this would be iffy. I need to send it to a client and I just can't as it doesn't work and they'll send to the printer and something else entirely will come out! Arg!! Spent hours already and it's not good. If anyone can help a very silly form newbee I'd be incredibly grateful! Thank you so much! Rebecca