So you have an access point somewhere. Everything wireless needs to connect to that central access point. It will probably also provide the IP address via DHCP to each client like your Tivo and laptop.

The first part to wireless is the security. It's likely you don't have the security configured correctly on the Tecra. This could be WEP, WPA or WPA2. It's possible your access point is setup for WPA/WPA2 and the old Tecra driver doesn't support it. It will tend to look connected but won't get an IP via DHCP.

Whilst you could go back to WEP (you'd probably have to reconfigure any other devices), it's very insecure these days. Even WPA(2) with a pre shared key isn't all that great I think now.

If you don't have any security set up, then you should fix that. When you connect a new client, it should request a shared key or "password" to connect to the wireless access point.

Once the wireless connection is made (you've got that) and the security is sorted out, wireless is no different to regular ethernet networking in terms of IP.

Possibly a new driver for the Toshiba will do the job if it's missing the security you need.