gpg-agent and ssh-keys not working anymore

[Joke de Buhr]

Usually I use the gpg-agent to manage my ssh keys. But now it doesn't work 
anymore. 

A few days ago I lost homedir and everything got lost. I rebuild the gnupg 
configuration to use the agent and the has ssh support enabled. I generated a 
new ssh key and added it to the agent via ssh-add.

Now every time I try to connect via ssh the pinentry window pops up and asks 
for a password to unlock the key. But pinentry always says the password is 
wrong and I keep getting the error message "Agent admitted failure to sign 
using the key.". 

The passwords are enter correctly and the ssh public key was added to 
authorized_keys. I tried generating new ssh keys but the problem is always the 
same.

Anyone any ideas?
Thanks