Smart keys start car in slot but nothing else

Long story, so please bear with me. I've been reading through the forums and found plenty of people with the (almost) converse problem; but not this exact problem.

A couple years ago, my wife lost her keys and we had to get a new key for her 2004 Prius. I had the 2nd key so it wasn't a huge deal. A few weeks later, she found the keys so now we have 3 keys for her Prius. I almost never drive my wife's car. Every time I do (with my smart key), I have to put the smart key in the slot. I figured it was just because the battery in the smart key was dead and I didn't care enough to replace it.

Fast forward to today. I went to drive my wife's car with my smart key and I finally decided to change the battery. After replacing the battery, I tried to lock/unlock the car it didn't work. I took the battery out, tested it (even though it was a fresh battery), re-seated it and tried again. Again, no luck.

Now my smart key is pretty beat up. In fact, the panic button is missing. So I figured maybe it's just broken. Fortunately, we have the 3rd smart key. I grabbed it, replaced the battery and tried it out. Still no luck. Two broken smart keys? Seems unlikely. And, indeed, they're not completely broken. Both keys will allow you to start the car when inserted in to the slot.

Here's a summary of where I stand. My wife's smart key works perfectly. I have 2 other smart keys that will allow you to start the car when inserted in to the slot, but nothing else. The lock/unlock doesn't work. The smart entry doesn't work. The smart ignition doesn't work.

I've know the dealers typically charge ~$100 to reprogram a smart key. I'm not at the point where I feel the need to do that, simply because my wife's smart key works fine. But is there some way I can fix this problem on my own? Is it possible that the two broken keys don't really need to be reprogrammed? After all, they're still performing the most important job - starting the car. Perhaps they just need to be... re-synced? Here's hoping.

Thanks in advance,
Bill