I'm trying some things out in the ethereum wallet but it keeps guessing the amount of gas wrong. How do I send more gas in the ethereum wallet?
I do not believe it is possible from the UI that the mist wallet provides. You will need to go commandline and use the geth tool. Then you can just unlock your account and perform a transaction and define the amount of gas you want to send.
RPC doc related to function sendtransaction : https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sendtransaction