Can you check your web server logs to see if it provides more details than just the basic 500 internal server error? Usually that is accompanied with some sort of detailed PHP error that you could see in the logs.
This isn't something I've had other reports about, so there must be something unique about your server/site configuration causing it. Can you try disabling other plugins to see if the problem goes away? Then you could re-enable them until it comes back so we'd know the culprit.
