Did you use an IR Pro to try and learn the codes?
You are supposed to position the remote you are learning during the capture test phase in such a way that the frequency stays consistent before you move on to the actual IR capture phase of the operation.
Further, the pronto version you can steal the hex codes out of is located here:
[Link: remotecentral.com] I know its a 200 and not a 300 but it will probobly work fine