'max_user_connections' and forum down

[Maxtor]

After upgrading from 3.x to 4.x , and after finishing all cron jobs for indexing etc, I get this error really often: 

User maxtor78_frsy already has more than 'max_user_connections' active connections

I have check my.cnf and i have max_user_connections=64 which was normal back in 3.x version.

I have run on mysql the command:

mysql> show processlist;

and i get this:

http://prntscr.com/gdqgwz

this is an example just before it exceeds 64 connections. Is it because search not working propertly? is it because its myisam and not innodb? how to fix this?

edit: i think if someone starts a "Search" , mysql query never ends, waiting to lock table....when more than 64 searches are made , forum goes down.

edit2: all searches never timeout. i have figure it out now.