If you make a change to a bug and you have a BUGLIST, it advances to the next bug. If you then click on next at the top it redisplays the bug report that is on the screen. So therefore what is happening is that when a bug is changed and the next one displayed the nav bar becomes one behind. Possible solutions, have the same report redisplayed after a change is made. Or fix the nav bar to advance one when a bug report is changed.
Fixed. Bugzilla now reloads the same bug report that changes were made to instead of advancing to the next one which was causing the nav bar to be one number off.