You can try deleting/moving your binary wallet file (default name wallet.bin) and just keep your keys file (wallet.bin.keys), and then let simplewallet rebuild the binary file. If you're moving a wallet file from 32-bit to 64-bit this can definitely be an issue, also moving from *nix to windows I think.
Just letting others know,
I had a similar problem, everything worked well up until 8.8.2, windows 7 64, this above helped to resolve it with one of my wallets, another wallet seemed to open but wouldn't handshake with the daemon, tried deleting everything but the wallet keys, saving, reopening bitmonerod, no spaces..etc. nothing. Again some wallets seemed to work, but some reason this one not.
Restarted computer. worked. Try that if yours isn't working for whatever reason. Explanation, I have none. I don't think it was port or antivirus related.