为什么我的Apache文件权限被重置？

We recently switched from using PCs at work to Macs, so I'm new to the *nix way of doing things. I have the default Apache running that shipped with 10.5, but I've noticed that when I drag files from a Windows server to my machine, the permissions are changed. Specifically, I'm writing data to an XML file, and occasionally after swapping some files back and forth, it stops working.We recently switched from using PCs at work to