Yes, can confirm that issue - searching for caches by country where states are supported by GC results in a 500 internal server error since the last update/fix when trying to use "all states".
Also it happens to me.
http://www.geocaching.com/seek/nearest.aspx?country_id=186'>http://www.geocaching.com/seek/nearest.aspx?country_id=186
Thanks for the fast first fix for filtering cache types.
When I tried the above link I also get 500 after hitting the button.
If I start from http://www.geocaching.com/seek/nearest.aspx and select a country it works for a search for all caches.
But there are other issues:
search for all Event types results in the 500 error for some countries, not all: Ireland, England, Germany, Austria are bad. I think Slovakia, Netherland, Belgium and Poland are ok. Really strange behavior, I think with Finland first it didn't work, then it did work.
Searching for individual event types works without problems.
All event types returns only events and mega events, CITO events are not included.
(why I am doing all those searches? you can win a 2011 German reviewer coin http://www.stash-lab.de/?p=1238 )
Another big bug, not sure if this is related to the update:
I wanted to discover a geo coin which I saw at an event and was logged in the event, but I made a mistake writing down the coin code.
So I posted a note to the coin "saw it but have the wrong code"
Then I tried this: I changed the note to a discover log. I was really surprised that it worked without entering a code.