I'm having the same issue. My tablet shows 5.92GB total space. The list of Apps, Pictures, Audio, and Downloads adds up to 2.47GB. The tablet shows 510MB free. That's a huge discrepancy. And I'm sorry, but doing a factory reset is not the answer. This is obviously happening more often than a freak occurrence and what's to keep this from happening again? The talk about botched downloads sounds familiar, so it sounds like that's maybe a cause. I'll keep looking into that around the net.