The clips are not locked.

That would explain the light blue colour, because locking does not change that. Well, sorry I can't help any more right now. I'll look again later (in about 6 hours) if no one else has helped by then.
Tor

I don't see anything except dark blue triangles on my events. It seems no matter what I do to them they always stay dark. Could you post a screenshot of your screen (or that part) for us o see?

Every time I get light blue triangles is when my audio event is shorter (by about a sample or so) than the video event. Go to the event's right edge and zoom ALL the way in, maybe you'll see they're not the same length. (Part of the black frame/event gap thing *sigh*).
To fix them take the video event and make it one frame shorter, the audio will then be the same length as the video.

Oh. I was dragging seperate video & audio onto the timeline.

However, I can still put fades on both the audio and video when I make one shorter.

Can't find anything yet. Time for more info. Is this the case with all events in a project, just the ones on one track or just some of the events? Does it occur on another project (if you open a new one and drag some events to it)? If not, what's special about the one it does happen to?
Tor

I cannot figure out what is causing this. When I zoom in my events appear to be the same length. Some clips have a dark blue triangle on the beginning and a light blue triangle on the end.

Does anybody know what the color of the triangle signifies?

I don't think there is a connection between the light blue triangles and you not being able to make a fade. The triangles seems to appear when there is a very short fade of just a few frames. But you can easily adjust that up or down.
If you have set snap to frames and try to make a fade that is less than a frame (you can do that when the timeline is zoomed in) Vegas won't let you. You have to pull the fade so that it matches the minimum you have set. This behaviour might also be affected by what standard transition you have chosen.
Do you get a crossfade when you overlap two events?
Tor

I don't know the definitive answer, but here is what I just found by fiddling:

The light blue triangles only appear on the audio event.

They are (initially) light blue when the event start/finish point does not coincide with the start/finish point of the original captured media.

On my Vegas, the light blue triangles do not prevent me from creating fades in or out to the audio part of the event.

If I do create a fade in/out, then drag the fade back to a straight "cut", the light blue triangle turns back to dark blue.

What all this means I know not.

Peter,
When you make a short fade on a video track and zoom out very much (making the event shorter on the timeline) you will eventually see the light blue triangle appear. But you can still drag to make the fade longer or shorter.
There is a setting (in Preferences I suppose) that will make all cuts into very short fades. I imagine you could easily create a situation where you get light blue triangles on all events. But I still don't see how and why you should be unable to pull at them.
Tor

I think that the light-blue signal a small fade or transituib. So when the fade or transition is so small that the fade lines are not shown, the triangle is shown as light-blue. You can try it by making a few frames fade and change the time resoulution.

About the "can not add fade" - do you mean cross-fade between events - if so, you might have the automatic-cross-fade disable.

Udi

Yes, Tors and Udi, it's all becoming clear .... er

When I drag the original audio to shorten or lengthen it, then zoom right in, I see that Vegas does create a "minimal" fade - and this is indeed when the dark blue triangle becomes light blue.

Now, is this the "Quick Fade length" from Preferences / Editing - it goes down to 1ms but will not go to zero - even if you type "0" and click apply, it goes back to 1.