Weird network hooha

Ok, I'm trying to backup my data via network right now, but I can't get the computers to see eachother. I ran ping from the main computer (this one) and found the other computer just fine. I ran ping from the other computer, but could not find this computer. I double checked winipcfg to make sure I had the right IPs, and they're both on the same subnet, but neither computer can see the other in network neighborhood. Both computers, however, can access teh net. Any thoughts? And yes, they're both in the same workgroup.