In the checkout and patron details page, if the item has not been renewed yet, the number of renewals is displayed as blank except in the list of previous checkouts on the checkout page -- in that case, it is displayed as zero. The renew count should be displayed consistently.
Patch pushed to master please test
This bug is mentioned in: bug 5397: display renew count consistently http://lists.koha-community.org/pipermail/koha-patches/2010-November/012952.html
Looks good to me.