[vB 4.1.5]Constant errors since downtime

[Karnage22]

Hi, just wondered if anyone else has experienced this or can confirm that the issue is with my host.

Basically my site had some downtime yesterday morning due to a issue with my host, and since coming back up, the vBulletin "Currently Active Users" section at the bottom keeps emptying itself. It is supposed to show used logged in within the last 15 minutes, but it seems every 10 minutes it is just removing everyone from the list.

I have checked the vB cookie settings etc and they are all fine, i have even changed the activity timeout to 3600 (1 hour) but still after 10 minutes the list is emptied and it goes back to 0 before growing again as people click.

For example it will show 45 users online (23 members and 22 guests) and they have all been active within the last 10 minutes, and then suddenly it will say 0 online (0 members and 0 guests)

It seems to be happening because of a database error which is happening a few times a hour, my technical email has 500+ emails since yesterday morning with the error below,

Database error in vBulletin :

mysqli_real_connect() [<a href='function.mysqli-real-connect'>function.mysqli-real-connect</a>]: (HY000/2002): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
/home/applefix/public_html/includes/class_core.php on line 1317

MySQL Error :
Error Number :
Request Date : Thursday, September 8th 2011 @ 02:20:16 PM
Error Date : Thursday, September 8th 2011 @ 02:20:16 PM
Script : ******
Referrer : ******
IP Address : ********
Username :
Classname : vB_Database_MySQLi
MySQL Version :

I have disabled ALL plugins and addons etc and touchbb and some theme stuff and it is still happening.

I have contacted my host twice and they have "looked into it" and assure me the issue is not server side.

So now i have no idea what todo.

Any help will be much appreciated, thanks in advance