There are at least two different ways to read the challenge and i thin that different logger have used different interpretations:
A:
Looking at rule 6 you can log other caches after you have reached 666.
The rule imply that you can't log other caches before you reach 666 points?
ie the sum of the first n caches during the day shall be exactly 666?
B:
If you use a subset of any caches during the day to reach exactly 666 points the checker is a harder problem an i have to think how to solve it.
If you use A only 7 of the 10 last find are correct.
But the text below the images says it has to a continuous run that starts with first cache of the day. I think A i the correct interpretation and the checker is now implemented according to A
If B is correct it is harder to write a checker.
I think the problem is
http://en.wikipedia.org/wiki/Subset_sum_problem
I am not sure it is easy to implement i lua and if the algoritm will work in the allotted time for the checker.