I created a Samba share on my new Ubuntu 10.04 machine. When I try to access it from a Windows 7 client, I get network error 0x80070043 (The network path not found). However, I get this error when I click on the share in the Windows Explorer, so it seems that Windows does find the path. I already enabled NTLMv1, disabled 128bit security and made sure that NetBIOS is running. I briefly disabled the Windows firewall, it didn't make a difference. What could be the problem?
I was getting the same error randomly, and was never completely able to understand what caused it, and/or to solve it. But it disappeared after upgrading to the latest Samba release (3.5.2), so it was probably due to some bug and/or lack of full support for Windows 7 client.
Which versione of Samba are you running?