The search currently allows you to find a ticket using text found in the Subject. The search does not provide a facility to find tickets (whether open or closed) on the basis of the content of the detail (the thread contents).
Helpdesk support is assisted massively by searching for previous solutions (or indeed similar unresolved issues) reported by other customers.
A search which searches the contents of the thread and private notes of stored tickets would be extremely useful for a helpdesk, in order to quickly find solutions for new tickets where a solution is already available, or indeed to help solve an ongoing issue yet to be resolved.
I would like to see a 'Search Ticket Histories' facility in a future release.
Thanks.