Completely limited by LinkedIn and, we agree, completely annoying. We really wish there was a way to increase the size of the avatar and it's been requested in the LinkedIn API forums quite a bit, but so far, they've stood by their guns and said that's all we get.
If they ever allow us to grab a bigger picture, we'll definitely implement it.
Sorry for the trouble, but glad your happy otherwise. Should you need anything else, just let us know!
Alex