I don't think it happens that often.
With THAT said, I found a loose internal brace on my Fly Baby a couple of months back. The wing had inspection panels that "kinda" gave me access to the turnbuckles, and I managed to snug it back up again.
It loosened, and I was concerned that I had a nicopress slipping or other dire event. But I re-tightened it and did a better job of safety-wiring (used brass wire instead of stainless for better ability to wrap tight in a limited area). Checked it several times since then, and it's been holding.
I discussed the issue on a previous thread:
http://eaaforums.org/showthread.php?...ing-Techniques
Temperature-wise, I have noted one instance where hot temperatures resulted in control interference. Don't think it was due to the internal bracing, though, probably the wood.
http://www.bowersflybaby.com/tech/heat_controls.html
Ron Wanttaja