I've noticed several times that submitting posts containing a lot of BBC (Bulletin Board Code) causes errors with the database;
Error: "503 - Service Temporarily Unavailable".
I don't know if this forum's software, Simple Machines Forum, is to blame for this or our webhost's database. I'll be posting this at the official SMF forums to see if anyone can help me with this.
Remember, we're running beta software here, SMF 2.0 RC3 is not a final product.
Update #1 (23-may-10);
I'm pretty sure it is not SMF causing this, the error indicates it is on server level and thus having nothing to do with SMF. I've send the webhost an e-mail about this.
Update #2 (25-may-10);
Customer service of our webhost can't help us with the issue. I'll try it with SMF support.