[mme42]

Well, If you mean that you changed your cookie timeout to 60 seconds, I'd definitely raise that. That would mean that your users would have to log in again every minute. I'm not sure if that would cause your problem or not. I'd think that you could at least get into your admincp long enough to change the timeout value to something higher. But, if this started happening right after you changed it, then it's likely what caused it.

I can't remember if the tools.php file gives you an option to run SQL queries, but if it does you could fix this via a query. Or, if your host provides something like phpmyadmin, you could do it via that too.

The SQL query should be something like this:

UPDATE `setting` SET `value` = '900' WHERE `varname` = 'cookietimeout' LIMIT 1 ;

Be careful though. You might want to open up a ticket with vBulletin and get their help directly.