It would appear that your "default_wallet" is not using whatever seed that you have written down.
![Huh](https://bitcointalk.org/Smileys/default/huh.gif)
That is pretty much the only reason I can think of that you are seeing different transactions between the old wallet and a newly restored one.
Also, the program says that your wallet file is not encrypted? but you say you created an encrypted wallet? You should be able to open your wallet file in a text editor to see the contents.
Can you check the "Addresses" tab and confirm that the addresses in "default_wallet" and "wallet_1" are the same? (You may need to goto "Wallet -> Addresses") to get the tab to show up. Once on the tab you may need to click the ">" symbols to expand the address lists.
If the addresses are all different, then the seed you have is not for the wallet with the 0.018 balance.
If you right click the transaction for 0.018 and select "Details", you should be able to see what address that was sent to, copy that address and in the "wallet_1" wallet, goto the "console" tab and type:
ismine("ADDRESS YOU JUST COPIED")
and then press enter... If you get "false", the address definitely isn't in that wallet.