User ids not working

[Icheb]

I already asked this over at vb.com, but they advised me to ask this here.
Yesterday I installed the forum on our webhost and the entire system of user ids is not working at all, although it is working without a problem on my local installation, which should be identical. Every time I click on a user to view his/her profile, I receive an "Invalid user" error message and worse, I can't even login from the forum itself (the login via the Admin CP works).

Previously we were using the Ikonboard 3.11 forum and I used the converter for iB 3.01 -> 2.2.2 to convert the data. That was apparently a major mistake, since I was told on vb.com that the converter doesn't work for 3.11, although the forum does work on my PC, just not on the webhost.

Can someone tell me what I have to do to "fix" the user ids or maybe show me a way to repair the forum?

Icheb

[Xenon]

check with phpmyadmin if all users have an row in the userfieldtable, too.

if they don't you have to create one manually.

[Icheb]

They do have a row. I even made a clean installation on the server without any imported data or hacked files -> nothing. I still get the "invalid user" message and I still can't even log in on the main page.
What am I missing or doing wrong? It works perfectly on my PC and the webserver fits the system requirements (it runs on linux with PHP 4.1.1 and MySQL 3.23.51).

There has to be a way to fix this and I would greatly appreciate any help.

[tHE DSS]

Did you do the database conversion on your own computer, then upload the database to your webserver?

If so, what did you use to do that? Also, did the process of moving from your computer to your webserver run smooth... what happend, and what steps did you take?

[Icheb]

It also occurs when I installed everything on the server without importing / converting any data, so it has to be an issue with either the host, the software or a configuration mistake of mine.
The address to the board is http://www.a-s-charmed.de/vbulletin/ , I supplied this address in the members area so it's the public installation.
As you can see, everything is set to its defaults, and there are still the errors...

Edit: The issue has been solved, thanks to Steve Machol again!
It was a strange cookie which caused those error messages and I was close to reverting back to the Ikonboard because of all this ...

Icheb