Sharing :: Can't Access Files On A Computer On Home Network?

I am trying to transfer files from Laptop A to Laptop B. I can transfer files from B to A, but I can't transfer them from A to B. When I try to, I get an error message saying "Windows cannot access Laptop A".It then gives me the option to diagnose the problem (I'm using Vista on both laptops, by the way). When I click that, it gives me the error of "Cannot communicate with Laptop A. We pinged the remote host but did not receive a response".Laptop A is connected to the network according to it, it can access the internet fine and can access other laptops on the network fine. I have disabled the firewall, shared the folders appropriately, made sure they were both on the same workgroup (they are both on the default Vista WORKGROUP), and still nothing.