As you are well aware, there are two main categories in this blog. Contents are divided for home / small business users, and enterprise users. This is for a perfectly good reason. Having worked in both environments, I'm confident that people belonging to each group face quite different challenges. They have different problems and different approach to solving them. Usually the 'good' stuff is in the enterprise section - this is where the seirous things happen. Sorry, SOHO folks.
Recently I bumped into an interesting problem. One of our clients had an interesting problem of not being able to use two proxy servers at once. The symptoms were that whenever both linux-based proxy servers were booted up and working, connections didn't get through. The proxy servers were set up to handle incoming requests from the inside network, and proxy them to a specific 3rd party network. By saying "connections didn't get through" I mean that connections were initiated towards the 3rd party, out to the Internet, but no response was received.