Here's a strange one:  on a new MC Soft a sequence consists of a single clip (V1) that has to fade in from black at the start and fade to black at the end.  Fades are done through dissolves at the head and tail of the sequence.  When I go to the very end of the sequence where the picture should have faded to black completely, I can still faintly see the video.  In other words, it hasn't completely faded to black as it should have.  The same at the head of the sequence.  The first frame already shows the picture visible through the black. 

I've just checked, both dissolves are set to Starting at Cut and Ending at Cut. I've tried reapplying the dissolves, and I've also opened the same sequence on my MCA (its a shared project on Unity). No chnage. This is new, I haven't encountered it on any of the other systems here. 

Any help will be much appreciated.  MC Soft 2.8.1 XP SDI Mojo. 25i project (DV25 420 media) Unity MediaNet 5.0.1

I'm going to go ahead and guess that the sequence is the exact same length as the clip, which means that your playhead is going to be either parked on the very front of the clip or very end of the clip.  If you want to fade to and from black completely, leave at least one frame of black at the beginning and end of your sequence.  When it's parked on the end of the clip for example, it will show you one frame before it completely dissolves to black.

 That's pretty standard behavior for Avid. What I do as a workaround is to place a one frame audio clip at the very end of the timeline, and then globally insert about 10 seconds of filler between the last image and the one frame clip. That will eliminate your problem and you will get a clean fade to black.

 You've guessed right, that's exactly what we've done.  I've noticed now that adding filler to the front of the sequence solves the fade up problem.  Thanks for your reply, it should work.

Or you could just use dip to color transitions instead of dissolves, then you don't need to worry about head and tail frames.

I'd use Fade From/To Color rather than dissolves.  note that the end will still require on extra frame to fully go out

Or, if you don't want to add black at the end, you can always extend the audio by one frame, which will allow you to have filler there.

Or another trick that I learned a while back, if you don't want to worry about adding extra audio clips and then bringing down their volume in order to extend your timeline, you can do this:

Add an additional video track (although audio track would probably work too), and do an add-edit on the blank track somewhere near the end of the timeline.

Enter trim mode, and on the edit point on the blank track only, trim the point all the way to the end of the timeline.  It will stop your trim at the end of the timeline, but just let the mouse button go, and then click again right where you left off, and it will let you trim out past your last clip and extend the timeline.  No extra clips needed.