"In the lower and middle temperature ranges, higher temperatures are not associated with higher failure rates." Google's Failure Trends in a Large Disk Drive Population.
If your disks really live in a >45C environment, then I take it back.

There's a difference between "deriving from a free software program" and "using the output of a free software program." You can use gcc to compile non-free programs, just like you can use OpenOffice to write a non-free report or book. In both cases, the product of the program is non-free, even though the program itself and any derivatives of the program have to be GPL. Bison 2.4.1 is plain GPL3. Flex isn't GPL at all. GCC is plain GPL (v2 and v3). Check out the GPL faq.