something wrong with 'who' 'w' 'uptime'

["Bert Verslegers (Mobile)" <bert.verslegers@gmail.com>]

Hello, i have the following problem:

When i typ 'w' he gives me 2 users logged in.(correct)

When i typ 'who' he gives me all the users from the past 5-6 days.

When i typ 'uptime' he says 16 users logged in.

I saw some stuff about it, googled the whole day, something with
libc5&6 but what can i do about it, because nowhere is a solution
available

What i did already:
cp /dev/null /var/log/wtmp
cp /dev/null /var/run/utmp

i reinstalled 'shellutils'


What can i do to solve the problem?

Hope to get someone can help me, thanx in advance.

With kind regards,

B.