dear all , 

i am facing wiered behaviour here in K2 blackpoint , my enviroment as bellow.

2 SharePoint Web Front End servers ( NLBed )

2 SharePoint Application Servers all services duplicated ( K2 server installed here )

2 SQL clustered.

every thing were going fine , and i tested from servers and from end users machines.

now i have 401 unauthorized error, when submitting the form from out side the servers. and sometimes from the servers. 

now do i facing the double hub issue in this environment ?????!!!!!!!! as i understood from the documentation the communication path as follow

 request comes to  WFE servers

then WFE submit the credential to Application Server ( this is step one)

then Application Server pass the credential to K2 server ( this is step two)

some one is telling nooo ,, this is how its works

Step One : user submit the form to WFE

Step Two : WFE pass the credential to App server.

Step Three : App Server failed to communication to K2 server ... 

Any one know what happening here !! which scenario is the correct one , i cant take the decision from here. 

And please note , that the i was submitting the forms out side the server before.

Step 2 ) from the WFE to K2 Server