I should state that without passing any extra parameters (eg. since_id) I can get this to sign just fine, so I think I must be doing something wrong, but I'm not sure what I'm doing wrong.
Here's a sample of a request that signs fine and I get the statuses: GET /statuses/friends_timeline.xml? oauth_consumer_key=MY_CONSUMER_KEY&oauth_nonce=5074&oauth_signature_method=HMAC- SHA1&oauth_timestamp=1258345948&oauth_token=MY_ACCESS_TOKEN&oauth_version=1.0&oauth_signature=2DxAmJcAaJopQUN3qAW9Av5cSQY %3D HTTP/1.1 And here's the same thing, but with a since_id passed and it returns an Invalid signature message: GET /statuses/friends_timeline.xml?oauth_consumer_key= MY_CONSUMER_KEY&oauth_nonce=2748&oauth_signature_method=HMAC- SHA1&oauth_timestamp=1258347821&oauth_token=MY_ACCESS_TOKEN&oauth_version=1.0&since_id=5756495174&oauth_signature=NNee %2BAI%2F1Nc2xw9honQ2y1dwFA4%3D HTTP/1.1 The since_id is being included in the signature, but I've tried it without including the value and I get the same result. Any help at all would be appreciated, Thanks,