All bug reports are archived in a special category that is invisible by default. But if a you do a search, and the matches don't show in another category (e.g. because no query matches that report), the archive category, highlighted in blue below, gives access to that report.
If a bug report has information on it that has not been viewed, such as new comments, the blue "incoming" overlay is displayed. If a bug has changes on it that have been saved but have not been committed to Bugzilla, the gray "outgoing" overlay is displayed. A red overlay appears if there is a conflict.
To create a custom Bugzilla query paste the query URL into the New Bugzilla Query dialog. This enables support of queries that can not be configured via the dialog, and as such some query hits may not open or format properly.
You can explicitly state whether you want to work with cached copies of Bugzilla reports and avoid refresh with the server. In offline mode the cached bug copy is always used. In online mode the Bugzilla server is always checked for the latest report.