got error invalid signature when requesting token
<p>When am trying to request token for tripit oauth, I got the error invalid signature. 
My url is:</p>

<blockquote>
  <p><a href="https://api.tripit.com/oauth/request_token?oauth_consumer_key=c5676701706473430d016ac7dc58a0149333349e&amp;oauth_consumer_secret=90b7567665605fad847815949ce414f7078742d5&amp;oauth_signature_method=HMAC-SHA1&amp;oauth_timestamp=1304072442&amp;oauth_nonce=kllo9940pd9333jh&amp;oauth_version=1.0" rel="nofollow">https://api.tripit.com/oauth/request_token?oauth_consumer_key=c5676701706473430d016ac7dc58a0149333349e&amp;oauth_consumer_secret=90b7567665605fad847815949ce414f7078742d5&amp;oauth_signature_method=HMAC-SHA1&amp;oauth_timestamp=1304072442&amp;oauth_nonce=kllo9940pd9333jh&amp;oauth_version=1.0</a></p>
</blockquote>

<p>Please help me, where I am wrong ???</p>
