Authentication fails when using IWP from a different subnet
I'm seeing a very strange problem while sharing a database using Instant Web Publishing (IWP). Everything is fine as long as the machines are on the same subnet. They can get to the page, click on the database name, get the login screen, and log in as both guest or with a filemaker account name. The authentication is set to filemaker accounts only, and not to external authentication.
When someone from another part of the company (on a different subnet) tries to connect, they get to the IWP webpage, and see the list of databases, and can click on one. They then get the login screen. However, after this no matter what they do (i.e. try to login in either as a guest or with an account name), they get an error message saying that the file could not be opened by the supplied username/password.
This happens when the database is served using both FMPro and FM Server Advanced. In FMServer, I made sure the authentication was set to "Filemaker", i.e. its not set to external authentication. I also checked the accounts in the database with FMPro, and the authentication is set to only Filemaker accounts.
In the log files though, I see something very strange. When the login is denied, an entry comes up saying "authentication failed for xyz" where xyz is NOT the account name they entered on the login screen, but rather the login id of the user on the network - which Filemaker should not know anything about! Its almost as if its doing external authentication even though its not set to do that.
All pointers would be greatly appreciated, thanks,