Leaving aside very badly posted bug report, btw. NO MATTER WHAT you should always stick to the bug guidelines! It was not written this way to help you but to help Ashley find and fix the issue.
... that is actually true. Noticed that many times myself but always get distracted fixing the mess it created and forget to post about it.
With many events and event sheet "Search event" is indeed not working right. Just like the cmontville89 explained. Sometimes when events are minimized, in groups or just in deep sub-event tree Search may not pick every single event you are looking for.