Hi! There is another patch ready for cacti. We should include it. http://www.cacti.net/downloads/patches/0.8.7b/reset_each_patch.patch
Conrad, thank you for report. Sorry, I missed this report somehow but the patch was added in cacti-0.8.7b-r3 on 19 Aug 2008. So this bug is fixed. If there are other patches which are necessary to cacti I'll be happy to add them too - just open new bugs.