These are some of the bugs I hate the worst. When you have a plausible explanation about why it's slow, or fails sometimes, and it isn't under your control (or is way out of your purview), it's far to easy to stop lookingand not find your own bugs that exacerbate the problem. Because if you don't have a bug, and it is all that external problem, you just wasted all that time looking. Finding that bug later is especially painful, as you realize a little more time initially may have saved so many problems later. :/