Please help-I am on a big time crunch!  I have upgraded to a Nikon D50 Sigma 8mm and Manfrotto 303sph-I have my nodal point set and I am shooting and stitching for the first time with this set up.  I am really surprised to be having trouble at this point-I have not had stitching problems before.  I am not sure what is going on.
 
I am shooting at about 15° up with 4 shots-then one up and one down.  I also tried just shooting four shots at the same angle.  I tried shooting four shots and just one down.  I tried six shots..Nothing has worked.  I always have a hole in the pano.  The icons at the bottom always show that at least one shot has been left out.
 
What am I doing wrong?  I don't have the luxury of time on this and I am starting to get a little worried.  I should not be having this problem.
 
Anybody have any ideas?  I will check this constantly-so please don't hesitate to ask anything.
 
Thank you-Stephani

Oops-I accidentally posted this twice-I am such a dork!

If you mean by "hole in the pano" that "one of the images doesn't get automatically stitched, but you CAN perform a MANUAL stitch on that last image" and you don't mean "when all the images are stitched, either auto or manual, I still have a hole in the final pano" then the issue is there's something in the images themselves that cause the images to fail to be auto stitched.
 
A good example of this is a featureless ceiling, blank walls, dull lighting etc.
 
All you need to do is perform a semi-automatic stitch on the offending image to correct.
 
Also, using the D50 with the Sigma 8mm you need only 4 x shots with a 15 deg incline for a full 360. you'll have a hole at the bottom of the pano though.

Not sure if this will help but here goes:
 
I have a similar setup: D70 with a Sigma 8mm and a NN3 (not as accurate as a Manfrotto but good enough).
 
I found that 21degrees stitched perfectly. 21d? Yes, after some experimentation the number is etched in my mind.
 
Good luck
 
John Purdie

Thanks guys for the help.  It seems as though there is something that is causing the image to fail to be stitched.  In the series of images on the image strip-I don't have a green square in the corner of that image.  
 
I will try the manual stitch-I have not ever done that before.  
 
Did the 21° leave a hole at the bottom that was larger than a tripod cap?   Are you guys having to PS the arm of the head out or does the upward angle take care of that?
 
Thanks again-Stephani  

Hi Stephani
 
With 4 around at 21d and 1 down the arm will clearly be visible and if you don't want it there you will have to take it out in PS or similar.  
 
My guess would be that you haven't got the lens set up quite on its nodal point. It's worth experimenting if you're not quite sure. I assume you're lining up the gold band on the Sigma.
 
Good luck with your looming deadline.
 
JohnP

Yes sir-I have it lined up and I have taken test shots and other than a missing shot in the pano-things are lined up correctly.  I don't see ghosting or objects out of place.
 
I took the shot in my kitchen and let me tell you-if something were out of place I would have seen it!  My kitchen is such a wreck-there are things everywhere on the counter-lots of good stuff to analyze for ghosting.  It all seems to be in place.
 
My kids are both sick-so I have not had a chance to try the 21°.  The delay is making me a little nervous-but my babies are always my priority.  I am glad you guys are here for help or I would be a basket case!
 
Thanks-Stephani

Hot Dog!  I think it worked.  I would sure like to get an opinion of the amount of space on the floor.  It is slightly larger than the cap.  Should it be or have I done something else wrong?
 
Is there a way to post a shot that is only located on my hard drive?
 
Thanks again-Stephani

17° seems to be perfect.  The hole in the floor is small enough for the cap and the everything seems to line up.
 
You guys are great!