electrophoresis rflp help - (Jul/03/2011 )

I am needing help interpreting what this means.
I have four lanes of completely digested dna. The smallest band shows up in one lane(this lane represents a normal dna pattern with three bands @ 104,82,and 37), but it dosn't seem to be present in the other three lanes (which represent heterozygote mutation showing bands at 141,104,82, and 37) where i can see only three of the four bands. Why does the small band 37 only show in one lane?

What would your hypothesis be for this situation?

hint... I think you are doing homework, so if you can come up with some ideas, we will be much more likely to be helpful. The answer probably has to do with moles.