Not all ethernet devices will send a link pulse. Some will only wait for the device at the other end to send link and then start talking. This often happens when you try to plug two laptops together without a hub (but I've never seen that problem with desktops). This sounds like what's happening with your setup.

I'd suggest returning the WET11 and buying a WAP11 instead. It's the same price (12 cents cheaper at CDW) and offers many more features. Yes it can do what the WET11 does (be a client to another AP without bridging). Since it's got an integrated switch, you won't have the link problem that requires you to have an extra hub with the WET11.

Edit: fixed typos. My fingers are telling me it's bedtime.