The only thing that I have found to work is to not log in to your account, before posting. I've tried Firefox, Chrome, and IE, and they all have the same issue.
I went to reply to your post after logging in, and it gave me the server error. I log out, and I can see your post again.
The reality is that using a quality webhost service that provides maintenance is how these sorts of things are prevented. Another reality is that these services cost more than those that are limited to little more than store and serve.