The first one I'd use is quite subtle, but's easy. I presume for your message that the errant file seems to look okay in VI? Well, check the status line. If it says [dos] or [msdos] after the filename right after you load it, then that may be the problem. To fix that, do a :set fileformat=unix and then save it.
Next I'd try :set list to turn on CRs and Tabs. Use :set nolist to turn them off again.
Other than that, I'd say you were looking for the cchars or mchars options; VIM doesn't have them because it seems to always display unknown control characters as ^A etc.
HTH.
Wade.