Sorry all for the non-reply...
One of them is wrong.
Sorry, I couldn't resist.
Can't see without knowing the address you are talking about?
Maybe the import didn't get all of the addresses in your wallet? Guess it could be several reasons.
Export your blockchain.info wallet and compare the two. Just a thought.
Blockchain.info has an import bitcoin-qt wallet function.
Your best option is probably to contact blockchain.info support.
As has already been stated, without access to the wallet it is very difficult to determine which is incorrect.
If you still have the Bitcoin-Qt running with the wallet, you could try running the following command in the "Console" of the "Debug Window" under the "Help" menu:
That will tell you which bitcoins your Bitcoin-Qt wallet thinks it stall has. Then you can look on the blockchain.info website and see if those inputs exist and if they are spent already.
If they are already spent, or if they don't exist, then you probably had some sort of "double-spend attempt" issue that caused your Bitcoin-Qt wallet to get out of sync with the blockchain.
If the exist in the blockchain and are not yet spent, then the blockchain.info wallet is incorrect and their support will have to fix it for you.