Hi Jamie,
With the new version of Form Wizard Pro 2.6.0.4 released today, you can add this to your user.config
<add key="FormWizardPro:ForceSubkismetForRecaptcha" value="false" />
and replace the Recaptcha.dll with the one from our source code repository in the _libs folder and then Recaptcha should work in Form Wizard.
I hope they do take the fix upstream but I have this gut feeling they won't and don't care based on the not helpful response I got basically saying UpdatePanel sucks instead of being interested in fixing the problem. I emailed the guy the modified files with good comments around my changes but he never replied so far. People have complained online also for a long time that the Recaptcha plugin doesn't work in medium trust, its another easy fix I also sent with the UpdatePanel fix. I've been compiling my own recaptcha every time I updated it to solve the medium trust problem. It really isn't a very complicated control so if they don't take the fix I'll just either roll it into our own sources or I'll fork it and put it on Codeplex as a new project. I'll give them some time first though, he might just be too busy.
Best,
Joe