Glad this helped you root out that problem. Any idea why Electrum and Bitcoin-Qt wouldn't accept my private key for this account? I assume that's unrelated to your blockchain.info database issues...
Were your exporting in plain base 58 format (default)? Electrum & Bitcoin-Qt will only import private keys in "Wallet Import Format" which always begin with 5.
Yes... Anyway, it is moot now since I already emptied that account.