Hi Snowball,
As a temporary Measure - I would open my cPanel -> Advanced -> Error Pages -> Select Domain to Manage Error Pages -> Edit Common Error Codes -> Click on 404 not found and in there I would add html to add a link and a brief explaination as to why the viewer should click on it.
Something Like:
Code:
<br /><br /><br /><p><font color="red"><font size="5"> <b>404 - Sorry We are currenlty experiencing Temporary problems</b></font></font></p><br /><br/><br/></p>
Please <a href="http://www.yourforumaddress.com"> Click HERE<b></b></a> to enter our forum!<br/><br/><br/><br/>
forum.com appologises for any inconvenience caused.
Let me know how you get on with that.