Launching ST3 after deleting the most recently used project file causes the editor (in each tab) to render "empty" on subsequently-opened files, even when opening a new window. Closing ST3 and relaunching fixes the issue, and, curiously, showing the About Box does as well.
1. Create a new project in ST3 and save somewhere.
2. Close all ST3 windows making sure the window hosting the new project created in (1) is the last window to be closed (such that ST3 will attempt to restore that project on launch).
3. Delete the .sublime-project/workspace files created in (1).
4. Launch ST3. You will get an error dialog, rather than the ST3 interface, stating that "project [path] does not exist". Click OK.
5. ST3 will open and look normal. Open another project (creating a new window), or switch to another project (using the same window).
Files in the project opened will have tabs, but the editor in each tab will be "empty". I can see a subtle horizontal line (just slightly lighter than the Monokai dark gray background) in the horizontal and vertical center of each tab editor, stretching about 50% of the width of the editor. I have 'highlight_line' set to true so may that's the line highlight? Just guessing...
Workaround: Restart ST3 or, curiously, show the About Box. Tab editors are restored with file contents.
Env: Using ST3 build 3012 on Windows 7 x64, latest updates as of today (Feb 13, 2013).
I discovered this simply because I decided I no longer wanted a project after restarting my system so I deleted the project files (.sublime-project/workspace) and it just happened to be the project opened in the last ST3 window I closed before restarting my system.
PS: Otherwise, I'm loving the fast start. Awesome!