Yesterday, I was trying to deploy a web application and I had troubles with getting Remote Blob Storage (RBS) with FILESTREAM to work.
Whenever I was trying to store a blob larger than 1MB I would get a Win32Exception such as: “The network path was not found”.
I googled (binged!) and found the following thread: Network Path was not found.
I was a bit puzzled by seeing small blobs going through, but the solution was simple: set your damn firewall properly! 
Configure a Firewall for FILESTREAM Access
When you enable FILESTREAM on your Sql Server (in Sql Server Configuration Manager), you need to check “Enable FILESTREAM for file I/O streaming access” or again your large content won’t work. By enabling this, Sql Server is creating a file share named: “MSSQLSERVER” (by default).
Sql FILESTREAM needs the TCP ports 139 and 445 opened to stream its content using this file share.
So, a simple test is to try connecting to this folder from your Web Server: \\<sqlserver>. If you can access it and see the “mssqlserver” Share you should be good to go…
johonline's blog 
It is not enough sometimes. PathName() in transactsql get netbios name by default. This name in my case isn’t resolved on client machine. I call PathName(2) to get full server name, and this helps me.
would you please elaborate more regarding this change you have made? i am facing the same issue and ran out of solutions, please help