Post your VesionInfio (http://wiki.miranda-ng.org/index.php?title=Version_information) please. There are 3 modules for chats in Miranda - it will show which one you are using.
CPU: Intel(R) Core(TM) i7-2630QM CPU @ 2.00GHz [Intel64 Family 6 Model 42 Stepping 7] [DEP Enabled] [8 CPUs]
Installed RAM: 6056 MBytes
Operating System: Microsoft Windows 7 Home Premium Edition, 64-bit Service Pack 1 (build 7601)
Internet Explorer: 9.11.9600.17420 (build 99600)
Administrator privileges: No
OS Languages: (UI | Locale (User/System)) : English/English | English/English
Free disk space on Miranda partition: 3164 MBytes
Miranda NG Version: 0.95.2 build #9966 x64
Build time: 29 Jul 2014 10:47:32
Profile: C:\Users\Empire539\AppData\Roaming\Miranda NG\Home\Home.dat
Profile size: 27066368 Bytes
Profile creation date: 12 Jun 2014 18:51:52
Language pack: No language pack installed
Service Mode: No
Active Plugins (19):
AdvaImg.dll v.0.11.0.1 [2 Feb 2014 18:45:10] - Miranda image services
AIM.dll v.0.11.0.1 [29 Jul 2014 10:39:52] - AIM protocol
AVS.dll v.0.95.2.2 [29 Jul 2014 10:39:22] - Avatar service
BossKey.dll v.0.5.0.3 [6 Jul 2014 13:16:02] - BossKey+
CrashDumper.dll v.0.0.4.22 [2 Aug 2014 16:34:16] - Crash dumper
DbChecker.dll v.0.95.0.3 [29 Jul 2014 10:43:36] - Database checker
Dbx_mmap.dll v.0.95.1.3 [29 Jul 2014 10:39:24] - Miranda NG mmap database driver
Facebook.dll v.0.2.9.1 [27 Aug 2014 15:29:14] - Facebook RM
GG.dll v.0.11.0.3 [29 Jul 2014 10:39:54] - Gadu-Gadu protocol
ICQ.dll v.0.11.2.5 [29 Jul 2014 10:40:16] - IcqOscarJ protocol
Import.dll v.0.11.0.1 [6 Jul 2014 13:14:58] - Import contacts and messages
IRC.dll v.0.11.0.2 [29 Jul 2014 10:40:04] - IRC protocol
Jabber.dll v.0.11.0.4 [29 Jul 2014 10:40:22] - Jabber protocol
MSN.dll v.0.11.0.2 [29 Jul 2014 10:40:30] - MSN protocol
PluginUpdater.dll v.0.1.2.2 [29 Jul 2014 10:43:42] - Plugin updater
TabSRMM.dll v.3.3.1.7 [29 Jul 2014 10:39:50] - TabSRMM
Tipper.dll v.2.1.0.5 [6 Jul 2014 13:17:06] - Tipper
Twitter.dll v.1.1.0.3 [7 Jul 2014 13:59:18] - Twitter protocol
Yahoo.dll v.0.11.0.1 [6 Jul 2014 13:15:32] - Yahoo protocol
Protocols and Accounts:
-------------------------------------------------------------------------------
AIM 1 - Enabled 0 - Disabled Loaded
Facebook 1 - Enabled 0 - Disabled Loaded
GG 1 - Enabled 0 - Disabled Loaded
ICQ 1 - Enabled 0 - Disabled Loaded
IRC 2 - Enabled 0 - Disabled Loaded
JABBER 1 - Enabled 0 - Disabled Loaded
MSN 1 - Enabled 0 - Disabled Loaded
Twitter 1 - Enabled 0 - Disabled Loaded
YAHOO 1 - Enabled 0 - Disabled Loaded
MetaContacts 1 - Enabled 0 - Disabled Loaded
MYSPACE 0 - Enabled 1 - Disabled Not Loaded
Icon Packs:
-------------------------------------------------------------------------------
Proto_AIM.dll [29 Jul 2014 10:42:08]
Proto_Facebook.dll [2 Aug 2014 15:33:14]
Proto_GG.dll [29 Jul 2014 10:42:08]
Proto_ICQ.dll [29 Jul 2014 10:42:08]
Proto_IRC.dll [29 Jul 2014 10:42:08]
Proto_Jabber.dll [29 Jul 2014 10:42:08]
Proto_MetaContacts.dll [29 Jul 2014 10:46:34]
Proto_MSN.dll [29 Jul 2014 10:42:10]
Proto_Twitter.dll [7 Jul 2014 13:58:52]
Proto_Yahoo.dll [6 Jul 2014 13:17:56]
TabSRMM_icons.dll [29 Jul 2014 10:44:02]
toolbar_icons.dll [2 Feb 2014 18:47:34]
xStatus_ICQ.dll [29 Jul 2014 10:40:30]
xStatus_Jabber.dll [29 Jul 2014 10:40:32]
It's not under Options / Events, but under Options / Message sessions.
Sorry for the confusion, I meant the logging functionality which logs chats to a text file, not the message log in the message window.
It's there. Message Sessions / Group chats / second tab.