Wireless options and questions

Okay I own an Inspiron 5100 that is configured with a Dell Truemobile 1300 MiniPCI card through a Dell Truemobile 2300 wireless router. My younger brother has his Sony Viao Computer up in the third floor where the router is set up to his desktop. He has a X-Box connected to the router so we can play Halo 2 on X-Box Live. Now I never really had any serious problems with the Router or MiniPCI card except for when it shows on my laptop that I was connected to the web but when I opened Explorer it would give me an error message. I would easily just power down the laptop, his desktop, the wireless router, and the DSL modem, wait a few seconds lets say 30 and power everything up again. The error message would be resolved and I'm back on the web, never really found a way to resolve this problem, I just keep doing the above but it gets old fast. So if anybody has another way to resolve this please post and I will check it out, I also removed the Dell 1300 MiniPCI card Utility and let windows configure the card.

Now I'm on the first floor and I get a decent signal of 11-24 mbps which is descent but I am looking for more speed. I just got a XBox with a XBox Live subscription and Halo 2 for myself, my brother was being greedy with his. Now I know I cannot connect directly from my room via Ethernet and another DSL modem believe me I tried, LOL. I can connect to X-Box Live via Wireless. I have done about 2 weeks of research and have found a solution to my X-Box Live Cravings. Check out what I have planned to order: http://d-link.com/products/?sec=1&pid=6 for Xbox Live compatibility, http://d-link.com/products/?sec=1&pid=11 for my laptop, and finally for the XBox console the http://d-link.com/products/?sec=1&pid=333, I did try to look for the http://www.xbox.com/en-US/hardware/xboxwirelessadapter.htm but nobody has it in stock. I have been saving money and planned on upgrading to a better wireless setup anyways. I just need a few responses from people who might have these products or other people who have suggestions. I need to know if this setup is the right way to go, I do not want to pay for a separate DSL line, also my ISP is Verizon DSL.

Also does enabling wireless security lets say 128 encryption weaken your signal? I have never enabled it but I have a McafeeSecurityCenter setup. Is there any benefit to having it enabled? Also I have picked up other people's signal on my laptop, does this mean they can pick up mine and connect to it and vice versa:smileysurprised:. If so how do I prevent this from happening? I Love this Wireless technology but feel that I am not fully protecting myself. Thanks for everybody's time.