After my initial installation woes, I'm now having a few issues with discovery.
Adding nodes manually works fine, but I have tried to run the Network Sonar Discovery a few times, each time with the same results - failure. 
I have attached a screen shot of the error message (Sonar_problem.jpg) and the APM/SAM discovery log (SolarWinds.APM.Discovery_[1344].log), it appears to be credential problems, but I have triple checked the username/password and all tests out fine.
Can anyone help shed some light please?
Thanks 
-------Update--------
I am thinking it is a credentials problem from SAM, on further testing the same domain admin account works fine on one box but fails on another, even though I can use the same credentials to RDP onto the servers. Our SBS server prossbs works fine, though our SQL server (pros-sql-01) does not. Both are in the same domain and I can use the admin account to access both machines via RPD and WMI data via perfmon.