Slightly off topic but I've been setting up a NAS at home and it would seem that sometimes the wireless settings on Windows (in particular MTU settings on Vista and Win7) may need some tweaking.
Essentially performance wired was fine - Gigabit Ethernet on cat5e cable. However when using wireless (g) to the NAS although the signal was fine and ave speed >30mbs, I got extremely slow performance and the systems were hanging (both Vista and Win7). Did find this piece about it and changed MTU appropriately and everything goes like the proverbial of the shovel at the moment. However in researching the topic it does say that this may affect connectivity from Windows to other devices such as media servers, PS3 and Xboxes when using wireless. This describes the behaviour somewhat ..
http://wiki.answers.com/Q/What_is_MTU_in_ps3_network Anyways its something to think about for those of you who are experiencing any hangs and issues on wireless which dont seem to be there when connected via wire.