As reported by Irmtfan: at:
http://xoops.org/modules/newbb/viewtopic.php?topic_id=76122
just put a echo in one modules/MODULE/xoops_version.php and see yourself.
It has a bad impact on site performance. specially it is worse in update and install processes when a module has some special scripts and functionality.
To solve this you should add one static $modVersions to store $modversion from all modules to avoid include xoops_version.php more than one time in XOOPS257|XOOPS256|Xoops26/kernel/module.php in loadInfo function
tested and it does solve the problem
Last edit: Tarik AMINE 2013-10-12
Change applied