[ZendTo] Strange behavior with IE 10 and 11

[Brad Dokken]

I am noticing strange behavior with Zendto on Internet Explorer 10 and 11. The user's computers are running Windows 7 and IE 10 and a couple are running Windows 8.1 and IE 11. The users successfully log in on the Zendto home page, but when they click any of the buttons on the home page (drop off, pick up, request a dropoff) the resulting page acts like they aren't logged in and they have to complete the request form and do the captcha. Everything works perfectly on Chrome and Firefox. 

Zendto is at the latest version, 4.11-14 and the OS is Centos 6.5.  Is anyone else seeing this kind of behavior? Let me know if you need more detail. 

Thanks for any help you can give me,
Brad