RTC 3.0.1.1 consumer error

I need to write a client application that lists the Project areas (and downwards like Defects etc) present on my RTC server. I intend to do this starting from the CCM Rootservices and extracting the CM providers. I have been able to retrieve the CCM rootservices document and from that the catalog URL.
I am trying to retrieve the OSLC catalog from the url :
https://rtc:9444/ccm/oslc/workitems/catalog using OAuth.
I generated a Consumer (Inbound) key with a secret.

I supplied this key and invoked the getRequestToken on the OAuthClient which gets back with a token successfully. But the subsequent getAccessToken request gives me an exception with invalid expired token error. I am unable to get past this error - can you help please ?