This is an extremely weird issue. If 17xSPe9avt1S5uL1Dtedoj7dQD6DgYozx1 is showing up in your imported addresses, and Electrum is connected, there should be no way for it to show a zero balance, because both blockexplorer.com and blockchain.info's address search agree that that address has a balance of slightly over .31 BTC.
You can tell for sure whether Electrum is connected by looking at the lower right-hand corner of the Electrum window. You should have a green dot there. If it's another color, then Electrum isn't connected properly, and that would explain why it isn't reflecting your balance yet.
Edit: I'll be unavailable for the next few hours, but I'll check in again when I can. I'm absolutely fascinated by this problem. I know this is no fun for you, but I love the strange ones.