Maybe you have a statement in the server's .bashrc that produces output. I, for example had this:
[[ -s "$HOME/.rvm/scripts/rvm" ]] && source "$HOME/.rvm/scripts/rvm"
rvm use ruby-1.9.3-p194@rails32
In this case the output from the rvm use will be (wrongly) interpreted as coming from git. So replace it by:
rvm use ruby-1.9.3-p194@rails32 > /dev/null