I've an issue with my Vista SP1 machine and the Smartsecurity Firewall. I'm unable to copy large files from my Windows XP machines (100mb and up) to my Windows Vista machine, when the Esset firewall is enabled. I'm getting the error "Semaphore timeout period has expired (121)" It works fine when I disable the Smartsecurity firewall on the Vista machine. There's nothing in the event log on the Vista machine, but on my Windows XP machines (where I copy from) there is: A driver packet received from the I/O subsystem was invalid. The data is the packet. I've found a workaround by creating a mapping on my Vista machine to the remote shares and to copy the files directly from the share to my Vista machine. (pull) This is an annoying issue. Reinstalled Eset Smartsecurity 3.0.650 and my networkcard drives but this does not help. Someone seen this issue before?