How can I keep two installations in sync?

[Lorenzo Martinelli]

Hello!

I wonder if somebody had a brilliant and fool-proof suggestion about this.

I have been keeping two Windows 7 installations of GIP in synch by 
synchronizing the cache folder to a NAS folder on both computers using a 
scheduled backup program.

However, at times, when changes are made to one computer, the other does 
not pick it up until the backup program runs. While the procedure works, 
it's not entirely reliable.

Is there a simple way to override GIP's default cache directory? If that 
were possible, I could point both installations to the same NAS folder 
and be done with.

--profile-dir <dir> does not seem to work in the options file (unless I 
am doing something wrong)

Lorenzo