Ok I found the problem !

My key was in 2048 bit ...

I created a new key of 1024 bit and it's working fine now !

Ok thanks ... could you give us the line before and after your key ? Ex : -----BEGIN DSA PRIVATE KEY----- and -----END DSA PRIVATE KEY----- Because I use Webmin for my server and not CPanel and I use puttygen to generate my key ... like a lot of people I think ... So I think that it's perhaps a prob...

@brock: what command line options did you use? the keys i've tried were all generated by ssh-keygen except for one, and i haven't been able to get andftp to use any of them. I'm also interesting by the solution at these problem ... My DSA key's (with password to protect them) generated by puttygen ...