5
It may be not that odd...
Not knowing how this "who's online" works but...
Before you login you are a guest, then you login and become a member.
The module is only aware of what people did just recently, not what they are doing exactly *now*. from the prints (in some access log(?)) it knows that a guest was here some time ago and that a member signed in. maybe the module doesn't remove the guest-entry even if there is a member signed in with the same ip. for what the module knows, you can be using two browsers, one with guest login and one logged in as a member.
And this seems to be true as now when I have been logged in for a while in my system, the guest account is no longer there is has been swapped out from the modules knowing (exceeded any time limit set...), but my member account is still leaving traceable prints whenever a roam the site...
BUT, what do I know... :)
Thanx
/stiffo