The cache is not at the listed coordinates. To find out where it is, you need to solve a little puzzle (or three).
This is the third (and final, I'm sure you'll be glad to hear) cache in my Regular Expression Puzzle series. To solve this puzzle, get the coords, and find the cache, you will need to have solved both of the preceding puzzles in the series:
as you will need to apply what you learn in one to the others. Enjoy!
You can validate your puzzle solution with certitude.
rinyhngr, errinyhngr, pbapngrangr, inyvqngr.