I only get the "500 - Server Error" message when clicking on "Search for Nearby Geocaches" on the home page after I log in.
It would then work the second time I tried it. But today I got the error message 3 times in a row. After logging out and back in it worked on the first try.
I am also having the problem of the search taking at least 40 seconds before it comes up with a listing. This has been happening for at least a month and it happens every time I log on. It never used to happen at all. What changed to make it so slow?