I'm told to upgrade but it doesn't work

When I started SmartFTP one day last week, it told me my version was about to expire, and gave me the choice to either purchase or update to the latest build, and gave me a link to get the latest version. I used the link to download the new version, installed it, rebooted, and still, evertime I start SmartFTP, I get the same prompt. I've tried this procedure many times throughout this week, and still the same thing. I'm using Vista Home Premium 32-bit. Is this a Vista issue of some kind? I LOVE SmartFTP, I don't wanna give it up! Thanks for any help you can give.