Interesting...I thought I was just clicking too quickly! I've had that error, and also some errors trying to send pm's, and when I go back to resend, they're gone! I've learned to copy and paste the long ones, just in case.
not that you havent heard this enough from everyone else, but im getting it too. it started about a week ago. ill click to read a thread, get a blank page, f5 it, and it'll load fine. or just hit the back button and reclick the thread. it loads fine the 2nd time.
to answer HH's question, its not happening on any other sites.
Honestly, it looks like your webhost is having problems, I've seen this problem on a NT server running the virtual directories and such associated with web hosting on an NT box It turned out to be the Front Page extensions screwing everything up and I doubt you have that on your server.
Oh, only dropzone.com and I go to a lot of things on the web everyday.