Ah well thats good! So all is working on the comms side, its just a config issue with SnapDrive.
Can you see the filer in the SnapDrive? If so, what you may have to do is disconnect the iSCSI drives from the server within Windows Explorer and use the SnapDrive "connect to disk" feature to establish the connection. Once this is done, it should allow you to select the volume and then the LUN where the iSCSI drive has been created. The next screen will be drive mount points and drive letters.
Just run through the wizard until complete... good luck!!
At the moment SnapDrive is unaware of the realtionship between the filer and the Server as it has been created manually and not through SnapDrive.
NB. Also just check the SnapDrive services are running.
I've seen issues with anti virus software in the past. In my particular case, it was Trend Micro. After system admin did an upgrade to OfficeScan Client version 10.5, Snapdrive was not able anymore to connect to the disks. Only message "Establishing connection" was shown. After disabling "OfficeScan NT Proxy Service" and restarting the Snapdrive services, everything worked fine again. Maybe this can help you to find the issue.
If you go into SnapDrive --> Server_name(Local) and in the Actions pane go to the "Transport Protocol Settings" you will see the options to add the filer to snapdrive. Make sure the username and password you have on the filer is also in here as well (as well as the correct protocol)