Maybe it is a wrong configuration, because in this forum it works well.
If I change the encoding in the logbook entry I get "Submit modified ELOG entry?",
and after clicking OK the entry is closed. Because this behavior is on all loggbooks
it must be a global config entry, but I dont know, which.
Here is the GLOBAL section:

Expand Selection page = 1
URL = http://sapelogs/
Date Format = %d.%m.%Y
Time Format = %d.%m.%Y %H:%M
Reverse Sort = 1
Menu commands = New, Edit, Delete, Reply, Download, Find, Last day, Last 10, Select, Copy to, Config, Admin, 
Login, Logout, Help
Find Menu commands = New, Edit, Delete, Reply, Download, Find, Last day, Last 10, Select, Config, Admin, Login, 
Logout
Password file = passwords.txt
Login expiration = 2
Admin user = ME
Suppress Email to users = 1
Self register = 0
Logout to main = 1
admin textarea = 150,45
Entries per page = 100
Mode commands = 1
Use Lock = 1
Supress Email on edit = 1
Supress default = 1
Summary lines = 1

Icon comment log.gif = Allg. Log
.....
Group SAP = .....