From my test site hosted on Dreamhost I tried to save a topic with a RegExp instruction:

<script type="text/javascript">var re = new RegExp("A"); var m = re.exec("ABC"); alert(m);</script>

Every time I get a 503 error on save:

The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Here on ~develop I can save the topic....

What does work is fooling the system:

<script type="text/javascript">var re = new RegExp("A"); var m = re.exe<nop>c("ABC"); alert(m);</script>

AC

Guessing from reports such as http://wordpress.org/support/topic/63283 this could be related to mod_security or the configuration of it at Dreamhost?

-- SP

https://panel.dreamhost.com/index.cgi?tree=domain.manage&

AC