OWA authentication

I have setup our internal OWA & ECP virtual directory's for Windows Integrated Authentication which is working for most people.  For some reason a few people are getting prompted to log in every time they launch OWA.  From what I noticed the login prompt is a Windows Security prompt that also includes an option to "Insert a Smart Card".  These users in question do have a smart card that they use to access some external websites.  

Is there a way I could get the Windows Integrated Authentication to work properly for these users and not get prompted with the Windows Security box?

Here is my settings:

[PS] C:\Windows\system32>get-owavirtualdirectory -server SERVER | fl *auth*,*forms*


ClientAuthCleanupLevel        : High
InternalAuthenticationMethods : {Ntlm, WindowsIntegrated}
BasicAuthentication           : False
WindowsAuthentication         : True
DigestAuthentication          : False
FormsAuthentication           : False
LiveIdAuthentication          : False
AdfsAuthentication            : False
OAuthAuthentication           : False
ExternalAuthenticationMethods : {Fba}
FilterWebBeaconsAndHtmlForms  : UserFilterChoice
FormsAuthentication           : False



[PS] C:\Windows\system32>get-ecpvirtualdirectory -server SERVER | fl *auth*,*forms*


InternalAuthenticationMethods : {Ntlm, WindowsIntegrated}
BasicAuthentication           : False
WindowsAuthentication         : True
DigestAuthentication          : False
FormsAuthentication           : False
LiveIdAuthentication          : False
AdfsAuthentication            : False
OAuthAuthentication           : False
ExternalAuthenticationMethods : {Fba}
FormsAuthentication           : False

---

----E----