vb 4, very slow in query global.php / forum.php

[gx123]

Hello,
the vbulletin forum at http://www.gamexeon.com/forum

is very slow for some user logged in from some location. It will take long time to finish 17 queries, about 5 to 10 secs.

the slowness is on global.php (shown by debug mode) or forum.php (shown by chrome)

here the screenshot:




surprisingly, if i open the forum in Incognito Window, the query will finish in just under 1 sec. awesomely fast.

some user surprisingly also able to open surprisingly fast even while logged in.

more surprisingly, the frontpage (http://www.gamexeon.com/forum) will randomly goes so fast. Page generation under 1 sec. But the showthred (example http://www.gamexeon.com/forum/gamexe...12-30-wib.html) will always slow.

any info how to fix this issue?

thanks