the private key that you generate with your watch-only wallet isn't your actual private key. i was setting up a wallet with the 1.9 client was experienced the same thing. instead of taking my word for it, you can do the following to check for yourself. the 1.9 client is very bugged btw.
1) save your private key on the watch-only wallet.
2) remove your .dat file and you will be left with "no wallet." now try importing your private key. Is the balance 0? that's probably because the private key is not the same as your original.
Thanks for your answer.. so if those private keys are not the real private keys.. what can they be used for then?
I thought Electrum was a pretty well known and used wallet.. it's full of bugs?
it's just another wallet address... but it's not tied to your current funds.