I have figured out why is does it the way it does, but I want it to STOP!  Based on the filter I put on the value field, it lists the legend fields as the lines start to show up from left to right.  So, if 200705 and 200805 have values that show up immediately, they are listed first.  If it takes two steps to the right before 200505 begins to satisfy the filter then it will show up next and so on.  So, my legend shows 200705, 200805, 200505, 200605.  That's probably not a big deal by itself, however, when the two charts sit next to each other, it is confusing.  I mean, for nearly the exact same chart, one of them has 200705 be the blue line, and the other one has 200705 be the red line.  It's really not acceptable.