I have the same problem having purchased Disktech. I have other NCH software and they just don't respond to requests for help. I've gone back to Epsom's Print CD, works everytime so I will be asking for a refund from NCH. I will not be trteated this way and ignored after I pay my money!
I have a Epsom Stylus XP-960 and although Disktech lists my printer as compatible, it does not work. I have absolutely no problem using Epsom's own Print CD software -works a treat every time. Needs sorting or I feel a refund and not so good feedback brewing!