I've never had the problem but I frequently (monthly?) cleaned it with a tool.
Not it's not a smoker problem.
Duke's solution works too. A LOT of it is dependent on what you're cooking and the humidity inside the smoker and outside the smoker. It's just condensation and yes, depending on what it brings with it, it could be nasty tasting.
Check a local hardware store, but this is similar to what I use: