Housebreaking can be difficult with dachshunds. While most dachshunds do eventually get the hang of it, it is not totally uncommon to hear things like "she's 95% reliable." Most likely it is their independent nature that makes them a little difficult to housebreak. It's not that they don't know any better, or that they maliciously want to be disobedient; it's just that they don't always see the necessity of relieving themselves outside (especially in bad weather), and they are willing to accept the consequences. Unless you're a real ogre, the minute you see one look up at you with his inquisitive, adoring expression, capped off with his brown, almond shaped, soulful eyes, you'll understand why they often get away with things. Patience goes a long way with housebreaking a dachshund.
