I believe this is a bug in vbulletin
 

I have a pretty virgin BB install with no load on it. I have my own mysql server and it works fine for everybody. This is a query error and it's not because of anything I hacked on. I have been screwing around strictly on the outside, with cookies and what not, and I have been externally deleting vbulletin's cookies. I'm rather frequently getting a database error. When I repeat the same thing it always clears up so it's no biggie. But perhaps vb should not be generating invalid SQL because a cookie was not where they expected it. Here's the notification I get:

Database error in vBulletin 3.5.0:

Invalid SQL:

SELECT *
FROM vb_session
WHERE userid = 0
AND host = 'xx.xxx.xxx.xxx'
AND idhash = '40fa72da473f960ef3027051150a9db8'
LIMIT 1;

MySQL Error : Record has changed since last read in table 'vb_session'
Error Number : 1020
Date : Wednesday, November 23rd 2005 @ 10:25:36 AM
Script : http://xxx.xxxxx.xx/vb/login.php
Referrer :
IP Address : xx.xxx.xxx.xxx
Username :
Classname : vb_database

If you think it's a bug then log it in the bugs database at vbulletin.com.

I externally delete cookies all the time and have never gotten any errors like this. There's more going on somewhere. ;)

It means you have an old version of mysql 4.1 that you haven't upgraded, its a mysql bug.

I'm running 4.1.7-max-log
What is the recommended release of mysql 4.1 for vbulletin?

The latest release is recommended, which is now 4.1.16 (dificult to find, release presented as current is 4.1.15).

Do you know if ..15 will solve the problem? I'll upgrade it if so. It is confounding my login integration efforts. This bug rears its ugly head when my outside code tries to select on the session table in vb. but it's reared its ugly head with me just being a normal vb user as well.... so I don't kknow if the problem is me or this bug.