502 Bad Gateway

I keep getting this error when I try to post. Anyone else?

Edit: Happened even when I tried to make this thread

Its happened to me before, but everytime i went back and tried again, i think i made 2 posts and i had to delete one :/

Up until 10 or so minutes ago I had no problems, but now almost every time I post I get a 502 error and I have to refresh the page to view the edit screen, then go back to the thread with my post.

edit: just happened again with this post.

If it's a browser problem, I'm using Google chrome on Ubuntu 9.10

This happens to me randomly whenever I click on a tab on the menu...

It gets annoying after a while =\

I believe this error occurs when the server is under load and there aren't enough PHP backends to service a request. I've increased the number of backends by 80% as a temporary fix; I'm currently looking into a more permanent fix (ie, requests should queue).