I set up Ubuntu with an ssh server

I'd like to connect from my windows7 netbook to the Ubuntu box via ssh.

I downloaded the latest version of putty - I am able to connect via ssh and run basic commands like ls and ps.

However if I run a "ps -aux" or a "ls -la" putty just hangs and I have to kill the session.

I thought it might be putty so I downloaded TeraTerm and SecureCRT and both have the same issues.

I have an xp laptop and when I run putty from this node there are no issues.

Any ideas what's going on here? I'm not sure if there is a problem with the emulator, windows7 or I dunno?