I was having difficulty inserting time... It only applied to some tracks, and then it moved my audio about 4 seconds ahead of my video. After some experimentation, I enabled "AUTO RIPPLE" and it seems that the problem is fixed. Does this make sense?
Click on the arrow next to the auto ripple icon in the toolbar. You can choose among three different auto ripple routines (only affected tracks, all tracks, etc). Your choice will depend on what other trackes, markers, etc you want to move when you insert the time. To keep the audio and video synched, select the tracks you want to sync and then "group" them (by selecting new group after right clicking on the affected track).
Insert time behaves a little differently than described in the users manual. If you want to insert time for all tracks, first make sure that no events are selected. Then do the insert time. If there are any events selected, the time will be inserted only for those tracks before the selected events.