ImageJ problems - I cannot get a correct count of objects in ImageJ, and cannot confirm (May/23/2008 )

I am testing ImageJ software to determine if the results are correct. I have 21 objects that I want it to quantitate. I have surrounded the objects with a rectangle, set the type at 8-bit, adjusted the threshold to color almost all of the 21 objects red, set the scale and the measurements and set the range to 0.5-infinity. The program counts only 18 objects. My questions are as follows

1. I think the threshold level is one of the problems with obtaining the correct count. Should I take the objects out that do not color entirely red. I suspect they are the ones the program is not counting.

2. How do I instruct the program to number the objects that it did count so as to confirm the uncounted objects.

Thankyou in advance for anyone's help.....................Ann