I have a similar problem, I have recently upgraded to Yosemite OS X and 1P was upgraded from V4? to V5. I enter my 1P license string but it will not allow me to purchase the dicounted 1P upgrade. ( I no longer require the Windows Version of 1P, but it will not allow me to purchase this either) thanks in advance.
@Reefshark64: Sorry for the confusion! 1Password 5 is a free upgrade from 1Password 4, so you already have a valid license! And I suspect this is why you're not being offered any upgrades: no need to pay for something you already have. Cheers!
Thanks brenty, 1P keeps telling me that my "Trial expired, click here to Buy" my original purchase may of been 1P v3 *(march 2013)
@Reefshark64: Indeed! Unfortunately 1Password has no way of knowing whether or not you've purchased it unless you register the app with your license information.
But the good news is that all you need to do is follow the instructions in the license email you received from your purchase and click the link to automatically install the license in 1Password to register the app and remove the trial restrictions. In that spirit, I've also resent your license information via email.
I hope this helps. Be sure to let me know if you have any other questions!
Glad brenty was able to help get your 1Password license situation cleared up. Cheers!