Hi Syamalan,
I think I found your problem. Look at both of you common.asp files (forum root and admin root) to see where your databases are being pointing to in those files.
Here's what I had to change mine too.
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'Virtual path to database
strDbPathAndName = Server.MapPath("../../database/wwf.mdb") 'This is the path of the database from this files location on the server
This one line in both had the old location of the forums db. I personally moved mine to another location which was causing my problems. I could do everything but admin the site settings.
This fixed everything.