I'm banging my head against the wall with this problem. I have a new MBP 13", 4GB Ram, etc etc. When I transfer files across my network (or the office network), it will consistently fail to transfer a few of the files. For instance, I just tried to copy 50 photos to an SMB share on our server here at the office. The transfer window show the progress of 50 files, but when I look at the folder, there are only 48 files. Sometimes I get less, sometimes I get all 50. The same goes for my home network to an SMB share. I've confirmed this failure over N and G networks. The AP at home and the office are different models and I went as far as purchasing a new one for home since I thought it was the problem. Same results. Is there some hardware error going on here with my wifi card? Is there any way to test it? Are the SMB shares the problem? Thanks for any help. I'm a convert from PC so I'm not great on diagnosing any mac issues yet.