Update: The problem is now resolved. Dropbox was able to get their domain off of the "malicios sites" list and now they are OK once again. Now if only they had an app for Symbian s60v5...
I love the dropbox service. I have been using it since it was in private beta. I even wrote a google gadget for dropbox to have immediate access to the service whereever I login.
Starting this morning, when I tried to access a file in my public dropbox folder, Firefox told me that this was a restricted site which was known for malicious attacks.
Since then, they seemed to have changed the subdomain from dl.getdropbox.com to files.getdropbox.com.
However, it is too late for me because the entire domain is now banned by my work proxy server. It does not matter that they changed the subdomain. The entire domain is now unavailable and unlikely to get unblocked any time soon, if ever.