[chef] knife bootstrap works and then fails with 401

[Z < >]

Hi List,
I already checked the chef common errors faq, and I winded up here, so here
goes.

I ran :
# knife bootstrap 10.161.95.253 -x root

Everything worked:
Fetching: treetop-1.4.10.gem (100%).10.gem
10.161.95.253 Successfully installed treetop-1.4.10
....
There were some errors fetching some gems, but thats not the core issue:
 ERROR:  Error installing yajl-ruby:

And then:
 Successfully installed chef-0.10.6
 1 gem installed
 [2012-08-08T19:40:24-04:00] INFO: *** Chef 0.10.6 ***
 [2012-08-08T19:40:26-04:00] INFO: HTTP Request Returned 401 Unauthorized:
Failed to authenticate. Ensure that your client key is valid.
 [2012-08-08T19:40:26-04:00] FATAL: Stacktrace dumped to
/var/chef/cache/chef-stacktrace.out
[2012-08-08T19:40:26-04:00] FATAL: Net::HTTPServerException: 401 
"Unauthorized"

kaboom.

Why?

Thanks!