Thanks for reporting the problem. It's annoying that gzip must invoke fsync, as 
that's way overkill compared to the write-ordering that is needed and fsync will 
slow gzip down, but I don't see any safe and reasonably portable alternative so 
I installed the attached patch on Savannah, here:

http://git.savannah.gnu.org/cgit/gzip.git/commit/?id=22aac8f8a616a72dbbe0e4119db8ddda0f076c04