In CiviCRM 4.7.5 and 4.7.6 (tested in both) we have a problem exporting event participants.
If you 'find participants' > search results screen > select all records, and then click 'export participants' no matter what options you select on the next screen (primary fields vs selected fields), only one record is exported.
The same behaviour happens if you use the advanced search tool to export any list of contacts - eg a list of members, so I think there may be a bug in the search results screen, as this is used by both of the above routes.
Using Event Reports > Event Participant List > Export to CSV will export a full list of participants, but doesn't have our custom fields.
Is anyone else seeing this behaviour / bug?