I've recently started using this, but keep running into the same problem. Twitter will return the error: or Quite peculiar, as it only happens on accounts that tweet every hour or so. It can't be IP related as it happens if I try Dropinbox on my VPS as well - yet when I post a normal tweet there and then, it works fine. Anybody has a similar issue? I'm hardly tweeting on the accounts in question and I assume you can tweet more than 3-4 times per hour!