Hello,
I have contacted the OP to inspect the issue. He was able to import the private keys on blockchain.info just fine.
He then gave me one of the private keys, which imported perfectly fine in both Electrum 1.9.2 and 1.9.5 on Linux.
However, when trying to import the private key on the Windows client 1.9.5, it fails.
Can someone else using Windows 7/8 please try to import the following private key to see if you can reproduce this?
5JB5KGpo2MeSgkKbRJrwoNVQPViuohZYa8NiURWqQt3bdcEsF6k
Don't have Win 7/8 at hand, but at least on Win XP it works for me (1.9.5):