I haven't used Rsense, but my first question would be: What mode are you
using for your .html.erb files? nxhtml? rhtml-mode?
-Steve
;; MuMaMo-Mode for rhtml/erb files
(add-to-list 'load-path "~/.emacs.d/nxhtml/util/")
(require 'mumamo-fun)
(setq mumamo-chunk-coloring 5)
(add-to-list 'auto-mode-alist '("\\.rhtml\\'" . eruby-html-mumamo))
(add-to-list 'auto-mode-alist '("\\.html\\.erb\\'" . eruby-html-mumamo))