that is not the same error that i get when it crashes. I get a max database connections exceeded error which could mean any number of things
Most likely this site is sharing a server with a number of other websites and those can contribute to the issue as well. It depends on how the host is setup. It could be max simultaneous connections, or max connections per hour.
For instance, our site would crash almost at the end of every hour. As soon as the clock would hit the next hour the site would be back running.
Yesterday the site crashed every time i logged on and started browsing. Other days i can browse fine without any problems.