So I send my public ssh key to a colleague to begin working on Android project, via ssh/svn.  It doesn't work.  I am convinced it must be a problem on his end because I use my key with about 10 or so servers with no problems.  I get the user/pass to his server to run an ssh-copy-id  and see what happens with my own eyes.  Shocker, it doesn't work.  Immediately I think there must be something on his server causing the issue, since last week I copied my key over to a new linux machine here in the office and everything worked fine.  I deleted the autorized keys from that new machine, and issued an ssh-copy-id and guess what?  It didn't work.  The key is in authorized_keys, but something is off.

So at this point I have my ssh key failing on the same machine it worked on last week.  Since this was my control variable, I knew something must be off on my end.  Ultimately, what I did was wiped my keys, rebuilt them(DSA) and received this error:

"Agent admitted failure to sign using the key."  which led me to this.  I didn't even wan to begin with that mess, and looked into just uninstalling and reinstalling ssh, at which point synaptic told me that it would also have to remove ubuntu-desktop.  Uhmm, no?

Plan E(or whatever we are on at this point) is to rebuild the keys a la RSA.  Which I did, and now everything works.  This makes no sense, and below is my log in case you can see a typo that I may have missed?  This involves HostA and HostB, hostB is my control, hostA is the svn machine.

stk@stk-sys76u810:~$ ssh smf@10.202.3.123 'rm .ssh/authorized_keys'
smf@10.202.3.123's password:

stk@stk-sys76u810:~$ ssh root@172.31.202.3 'rm .ssh/authorized_keys'
root@172.31.202.3's password:

stk@stk-sys76u810:~$ ssh-copy-id -i ~/.ssh/id_dsa.pub smf@10.202.3.123
smf@10.202.3.123's password:
Now try logging into the machine, with "ssh 'smf@10.202.3.123'", and check in:

.ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

stk@stk-sys76u810:~$ ssh smf@10.202.3.123
smf@10.202.3.123's password:

[[wtf?]]

stk@stk-sys76u810:~$ ssh-copy-id -i ~/.ssh/id_dsa.pub root@172.31.202.3
root@172.31.202.3's password:
Now try logging into the machine, with "ssh 'root@172.31.202.3'", and check in:

.ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

stk@stk-sys76u810:~$ ssh root@172.31.202.3
Last login: Tue Jun 16 08:27:32 2009 from 10.202.3.58
Linux HostB 2.6.15-29-server #1 SMP Wed Aug 29 14:26:14 UTC 2007 i686 GNU/Linux

The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.
You have new mail.
root@HostB:~#