Laptop no longer connects to internet via router wirelessly

Hi. First, I'm far to be an expert. I just tried the typical solutions to my problem that I describe below:

- I have two laptops DELL (Inspiron and Vostro)
- I have a router NETGEAR WGR614v6
- I always had both laptops connected wirelessly and another desktop hooked to the router.
- Some time ago, suddenly, the Inspiron no longer could connect to internet wirelessly. However, it could make it with a wired connection to the router. No time to spend on that at that moment, so I continued working that way.
- Now, I started to investigate a little and I could observe the following:

1) The Inspiron can see any of my neighbors' routers and can connect to internet. However, even it can see my router, it can not connect to internet. It can do it if it is via LAN.
2) The Vostro can see both my router and my neighbors' ones, and succesfully connect to internet.
3) Ping from Vostro wireless to router, OK. Ping from Inspiron wired, OK. Ping from Inspiron wireless, no way.
4) I decided to call a more educated guy. He also checked the firewalls but he said there was nothing affecting the connection. His conclusion was that a program like PCcillin (that automatically runs once a while) may have blocked the mac address of the router in the network card (at least, that is what I understood). He also said that blocking a mac address is incredible much easier that unblocking it, which may be a pain. His recommendation was to reinstall Windows. However, given that I have a dual booting system (XP - Suse), I'm pretty sure that the reinstallation may cause some conflict. I really do not want to pay the price of reinstalling Linux too. He also suggested to use a USB wireless connection and disconnect the laptop's one. It may be an option.

My question is if any of you think of any other possible cause of my connectivity issue. If not, is there any way to unblock what is blocked, in a not extremely complicated way?

Thanks a lot.

I have had the same problem with EVERY wireless router that I have come across. I do not think that it is Windows at all, because...
I was trying to connect to my router with this laptop. couldn't. So I tried to use another. Couldn't. I figured maybe it was my wireless CARD, so I plugged in a wireless usb stick, and both laptops started running fine. Both, when I only plugged it into one laptop. I would suggest to get the cheapest one if you don't already have one and try it out. I hope this helps you :-D

just check ur tcp/ip configuration , ur ip and g/w may have been configured manually. that cause connecting problem to mismatched g/w
also u may need to update the drivers .