If you close ("cold exit"?) sublime with an empty buffer, then you'll be in an "odd" state on startup, in build 2103. This probably depends on "remember_open_files" being on. Steps:
-File > New File
-Close Sublime via the Windows "X" button (or any other way to not trigger a hot exit)
Result: on launch, you'll have an empty buffer open, but it's not associated with a tab. Clicking on another tab "fixes" things.