Why do I get an HTTP 401 error with MGTwitterEngine?

After a long fight with OAuthConsumer, fixing method names, etc... I got MGTwitterEngine's demo compiled, but when I run it, the application quits with this in the Debugging Console:

2010-07-02 14:15:29.896 MGTwitterEngine[2076:a0f] Connection finished C235E35F-8开发者_StackOverflow586-45EF-97C2-XXXXXXXXXXXXXXXXXX
2010-07-02 14:15:30.572 MGTwitterEngine[2076:a0f] Request failed for connectionIdentifier = F96C9CA4-3CA3-4F6D-A402-XXXXXXXXXXXXXXXXXX, error = The operation couldn’t be completed. (HTTP error 401.) ((null))
2010-07-02 14:15:30.572 MGTwitterEngine[2076:a0f] Connection finished F96C9CA4-3CA3-4F6D-A402-XXXXXXXXXXXXXXXXXX
2010-07-02 14:15:30.585 MGTwitterEngine[2076:a0f] Request failed for connectionIdentifier = 65112043-4ADD-40C0-A2C8-XXXXXXXXXXXXXXXXXX, error = The operation couldn’t be completed. (HTTP error 401.) ((null))
2010-07-02 14:15:30.586 MGTwitterEngine[2076:a0f] Connection finished 65112043-4ADD-40C0-A2C8-XXXXXXXXXXXXXXXXXX
2010-07-02 14:15:30.635 MGTwitterEngine[2076:a0f] Request failed for connectionIdentifier = 2D4E7B72-DCF2-4C48-9EC6-XXXXXXXXXXXXXXXXXX, error = The operation couldn’t be completed. (HTTP error 401.) ((null))
2010-07-02 14:15:30.635 MGTwitterEngine[2076:a0f] Connection finished 2D4E7B72-DCF2-4C48-9EC6-XXXXXXXXXXXXXXXXXX

Can anyone help me? I am using HTTPS.

401 error means your are not authorized for this method.

try to authenticate first :)

First of all, try with a public accessible method like public_timeline