Basically I use the custom variable setting. Here are the relevant lines from my custom.el . I also included all my other custome variable org settings in case something was overriding the stamping...

'(org-time-stamp-rounding-minutes 5)

'(org-agenda-custom-commands (quote (("d" todo "DELEGATED" nil) ("c" todo "DONE|DEFERRED|CANCELLED" nil) ("w" todo "WAITING" nil) ("W" agenda "" ((org-agenda-ndays 21))) ("A" agenda "" ((org-agenda-skip-function (lambda nil (org-agenda-skip-entry-if (quote notregexp) "\\=.*\\[#A\\]"))) (o rg-agenda-ndays 1) (org-agenda-overriding-header "Today's Priority #A tasks: "))) ("u" alltodo "" ((org-agenda-skip-function (lambda nil (org-agenda-skip-entry-if (quote scheduled) (quote deadline) (quote regexp) "<[^>
]+>"))) (org-agenda-overriding-header "Unscheduled TODO entries: "))))))
'(org-agenda-files (quote ("/users/jrobins/org/work.org" "/users/jrobins/org/todos.org")))
'(org-agenda-ndays 7)
'(org-agenda-show-all-dates t)
'(org-agenda-skip-deadline-if-done t)
'(org-agenda-skip-scheduled-if-done t)
'(org-agenda-start-on-weekday nil)
'(org-clock-into-drawer 2)
'(org-cycle-include-plain-lists t)
'(org-deadline-warning-days 14)
'(org-display-custom-times t)
'(org-drawers (quote ("PROPERTIES" "CLOCK")))
'(org-emphasis-alist (quote (("*" bold "" "") ("/" italic "" "") ("#
" Highlight "" "") ("_" underline "" "") ("=" org-code "<code>" "</code>" verbatim) ("~" org-verbatim "" "" verbatim) ("+" format-font-lock-strikethru-face "<del>" "</del>"))))
'(org-fast-tag-selection-single-key (quote expert))
'(org-fontify-done-headline t)
'(org-hide-emphasis-markers t)
'(org-hide-leading-stars t)
'(org-remember-store-without-prompt t)
'(org-reverse-note-order t)
'(org-tags-column -120)
'(org-time-stamp-custom-formats (quote ("<%b/%d %a>" . "<WW %V.%w %I:%M %p>")))

'(org-todo-keyword-faces (quote (("WIP" . yellow))))
'(org-todo-keywords (quote ((sequence "TODO" "WIP" "DONE"))))

----- Original Message ----
From: Manish <mailtomanish.sharma@gmail.com>
To: Jose Robins <wu lfhomme13-rook@yahoo.com>
Cc: emacs-orgmode@gnu.org
Sent: Saturday, March 22, 2008 9:47:35 AM
Subject: Re: [Orgmode] Timestamp rounding not working

On Sat, Mar 22, 2008 at 9:38 PM, Jose Robins wrote:
>
> I use org-mode 5.21 with xemacs 21.4.21. When I clock in and out of a task,
> the time stamps don't seem to round off to 5 minutes as I have specified in
> the custom settings. Isn't that what the time stamping rounding setting is
> supposed to do? Or do I have that wrong?
>

Can you please show the setting from your .emacs?

-- Manish