This answers my question below and an issue that has come up since 10.1.
First if the inspector is open, you cannot extend the event browser. This has driven me crazy for quite some time now, and I didn't put the two together.
2nd, if you find that there are playback issues when trimming on the timeline, closing the inspector will solve this problem as well. Not sure if it's an issue with the newest macs but my late 2011 3.4 i7 16g won't play back properly with the inspector opens.
Third, closing the inspector whilst holding the option key will reveal fcp 7 style tracks in the timeline.