Event Participant Showing in Event Report, but not in Participant Search Results

[Fred]

Hi. We have an event with a fee for 'RV'. When a search is done for participants who have paid the 'RV' fee, one of the participants doesn't show up, but they do show up when an event report with the filter set to 'RV'. The fee shows up on the individual's record when it's viewed/edited. What could possibilily  cause this to happen? The individual record includes payment for the 'RV' fee. They show up in an event report with the filter set to show the 'RV' fee level, but they do not show up in the results when a 'Find Participants' search for 'RV' is done. This is happening on a Joomla 3.4.1 site running civiCRM 4.5.8