I was using this piece of breadboard for choosing component values for a simple circuit. I'd bought it some time back from a typical Chinese ebay seller.
While testing the circuit I just couldn't get it to work. I double and triple checked all the connections and swapped components, but it still didn't work. It was only when I actually started metering it out that I discovered that the breadboard does not have continuous bus strips at the top and bottom. Instead they are divided into three sections each with no markings on the front to indicate that.