Need help with forum password

[JoomlArt]

Hi all !

My forums appears a problem below :
Before 2 days some sub forums is set password for accessing so forums's user can't access to that forums. when access it displays the message :

Your administrator has required a password to access this forum. Please enter this password now.
Note: This requires cookies!

I have go to forum manager and remove password for all forum and it is ok.

But now some sub forums is set password again , i don't understand why.

What is cron or plugin can change access password for forums ?
I am using VBB version 3.8.1

Thanks you very much for help.

[Marco van Herwaarden]

No plugin or cron should do that. Please recheck your forums settings.