@annerl, are you trying to claim your ETC from the fork? then rest assured because a replay protection has been implemented on ETH's side (not sure about ETC), so just send your ETH first and your ETCs are good to go. Also, make sure you are using the latest version and not a fake phishing wallet.
This would provide a way to send transactions that work on Ethereum without working on ETC or the Morden testnet.
It's quite alarming that the support doesn't know ETC is on a separate blockchain, it's a very basic info and it sheds light on how their employees are screened/picked...