Faces suddenly missing I was working on something in Blender and when I loaded it up I noticed some faces missing. Thought the best way to fix it'll be filling it in. Problem is that some faces still stay transparent. They don't even show up on my texture area. How can this be fixed?
It is hard to comment without seeing the blend file, however, you can try:


Un-hiding all faces (Alt + H); and/or
The Make Normals Consistent commend. Highlight all faces (using A in face mode), and then access the command by hitting space bar and searching for it.


I would also run the Remove Doubles command, just to make sure you have not created a face on top of another face when trying to "fill in" the gaps.