when I got this problem ( Connection Failed Reason 0) after some investigation and experimentation the following worked
1. If logging on remotely using a script to map the drives so you get a S:\sims drive mapped >> change the names of the servers to their internal IP addresses in the logon script
2. on the local machine go to the sims installation in c:\program files or where-ever
>> DELETE the Connect.ini file ( make sure you are on the LOCAL Machine NOT server !) Then try to run SIMS or Pulsar.exe - it will give 'can't find connect.ini' error
>> BROWSE to the Connect.ini file on S: Drive Sims folder
>> connection became established