I actually never managed to connect using WP7 version myself so we in the same boat.
The reason I did this version is cause someone requested it, but when I did WP7 version I didn't hear any response back from him, so I assume he abandoned the idea of developing something in WP7.
I guess now I can try to look at it again.
Can you send me a sample app that I can use to connect to SSH using WP7 and I will try to debug and see where the problem?
I never developed anything for WP7 so it would be first for me.