I am having a problem like this. It looks like the same problem. I am trying to import my old Toshiba laptop which is running Windows XP Pro onto my server which is running Windows Server 2003. I have the simple file sharing turned off. There is no anti virus or firewall software running on the laptop or the server. The only firewall on the network is where the Internet comes into the network.
The files are being created in the network share and it does show that the files are of the size I've specified, but this could just be VMware Converter on the server telling the files to be that size, at least that's what I'm guessing.
I got to thinking a moment ago that maybe if I ran VMware Converter under the server's administrator account instead of my account which has Administrator privileges it might work, but it didn't.
I installed VMware Converter onto the laptop to see if I could simply create the image on there, but, got the same error message. I first tried to save the files onto the local hard drive of the laptop and I tried to have them put onto the network share. Either way, it still failed when it got to 97%.