When I try to log in to Twitter in FaceBook I get the following error:

RFacebook environment information
This shows you at a glance the information that RFacebook has populated for you. 
More information at rfacebook.rubyforge.org. Please report RFacebook bugs here. 

FacebookController 
fbsession OK  session is ready to make API calls  
fbparams OK  user 1247880178 
added 1 
session_key 860bc821aad4c8b0851af3fc-1247880178 
in_canvas 1 
profile_update_time 1209796848 
expires 0 
time 1210151613.6903 
friends 36909295,506925317,510455855,527756044,542643188,555252550,613783796,613981621,629417020,629888622,638331658,665
359493,667704317,668490759,670869888,679968114,681049972,684175228,691137587,691768702,691927823,695760316,696248354,702
347809,703871564,704446907,739261386,741148621,751672403,758763735,760662982,776695127,813374853,1004063831,1010873754,1
018673201,1035464189,1038587556,1140892549,1245634800
api_key 7cc3dc042ec019b913300d1e7559aad9 
ext_perms status_update 
request_method GET 
locale en_US 
position_fix 1 
 
in_facebook_canvas? OK  yes  
in_facebook_frame? OK  no  
facebook_api_key OK  XXXXXXXXXXXXXXXXXXaad9  
facebook_api_secret OK  XXXXXXXXXXXXXXXXXXc6f4