When I start M-x eshell it gives me message "term-set-escape-char: Key sequence M-x starts with non-prefix key". It doesn't give me prompt in the eshell window.
eshell-prompt-regexp is
"^[^#$\n]* [#$] ".
eshell-prompt-function is:
(lambda nil (concat (abbreviate-file-name (eshell/pwd)) (if (= (user-uid) 0) " # " " $ ")))
I haven't been able to reproduce this. You don't indicate what your hardware platform is or whether the problem still occurs when you start with just a minimal init file. I googled and found a similar bug report here: http://comments.gmane.org/gmane.emacs.bugs/15859. That user was on Windows and the issue was corrected by removing a key binding that they had in their init file.