MySQL lost connection errors - related to DB session sto

Simply use the native win32 mySQL driver (It is available as a gem).
The ruby one got issues with win32.
The pb is very random. You can have everything working fine for a
while, then suddenly got the connection lost errors.

I agree with Benoit, you definitely need to install the native mysql
driver. Just do:
gem install mysql

and then pick the driver for win32, it will resolve your problems.