My phone reports 131MB internal memory use but when I add up the sizes of all apps in internal memory, it doesn't add up even to 100MB. I don't have any media whatsoever in the phone. What is the culprit for my ~30MB loss?
Edit: The storage space started to drop significantly after I have upgraded the stock Android Market app to Google Play Store app. After this, I think Google Play Services has been downloaded, which takes up a lot of space. Still, it should not be taking up that much space. Strangely, when I plugged my phone to my PC via USB, the reported internal storage dropped to 70MB again. I can't find an explanation for this.