I've noticed that it's faster using a wired connection to my router vs. wireless. It used to take 2-3 hours to download a 0.8-1.0 Gb game demo. Now it's less than 20 mins. Someone in another thread pointed out that times are slower during "peak" times, for example on weekends and weekday evenings.
Hmm, I think I might have a bit of an explanation for this. I run three different access points (AP) through my house to provide internet to different areas of the house. All AP's are designed to act as AP's and bridge to the main AP. I use Netgear 80.11g APs. Every once and a while, I would noticed the the network seemed slow. I would think it was my ISP, but I would test at the wired connection next to the ISP box, and that would be fine.
I would have to shutdown all the wireless computers and AP's and then bring them all up again. Once I did that, the network speed was once again normal. This happened about every three months. I kept updating the firmware, which did seem to help alot, and the problem seemed to be fixed.
My son came home from colllege in April. I once again noticed a slow down on the wireless net. I tired rebooting everything, but the slowdown was still there. I realized that his computer was still on the net. I asked him to reboot it, problem solved. Turns out when he would run LimeWire, it clogs the wireless connnection.
So, look for a couple of things that can be affecting your wireless connection
1) Make sure all the wireless AP's have their firmware up to date.
2) Test individual computers as they connect to see if they are affecting traffic. Some may have some viruses
3) Check to see if anybody is running peer to peer software
