This always seems to be a problem when you introduce a new wireless router in the home. A couple of questions forst.
1. Did you give it the same SSID as your old access point?
2. Are you using\tryign to use the same wireless security as your old Netgear router?
If so then I suggest you remove the wireless connection in Windows and re-detect, and set it up again, and if you can do the same with the Blackberry. I also would NOT use WEP, it's simplly too insecure these days.