Please HELP! advanced options deleted

Hi everybody,

I recently had a problem with a clients WB site: suddenly the pages except for the homepage couldn't be accessed anymore. I found the solution in the advanced options: all the fields in the category server settings were empty! But the site had been working excellent for weeks before this happened.
Now here's my question: how can this be?

- Is it the user/client who must have been accessed the advanced options page and changed the settings (which I don't believe he did, because he doen't have enough knowledge what this all is about ...)
- Can this have happened by any other user mistake?
- Could it be that the site has been hacked and some stupid person found it funny to clear all these stetings? Should the passwords be changed?
- Could changes by the provider have caused these problems?
- Any other idea?

What was really strange is that the radio buttons server type (Linux/windows) were both empty! How can you do this as a user?

I would be very grateful if someone could help me to find out how to avoid that anything like that can happen again on my clients sites.

Thanks in advance & regards
Jochen