A call to SSPI failed, see inner exception

Dear all,

I have error “A call to SSPI failed, see inner exception.” when open RTC in Terminal Server.
The strange thing is this issue sometimes happen and sometimes does not happen.
When open RTC to database A, this error is appear. But, when open RTC to database B, this error is not appear.
Database A and B is in same server (database server).
I am using NAV 2009 R2 Build 32465 with 3-tier installation (database server - middle server - terminal server).
Why this error is happen?
First I had this error, I restart the terminal server and this error is not happen.
Second I had this error, I restart the terminal server and this error is still happen. So, I restart middle server too and this error is not happen.
Now, I had this error again, I restart the terminal server and middle server, this error is still happen. So I restart database server and this error is not happen.
This is so strange. What is the cause of this error? How to prevent and solve this error?
Because when connect to database B, this is not happen…
Please help… Thank you…

This the event viewer of this issue :