Some REALLY weird Database trouble

help its like im living in the past on my forums :

my users can see the up to date database as normal but if a user creates a thread then gives me the url it says that is an invalid thread id but all the users can see it :angry: strange ........

i dont know whether this is just for the admin or is has somethin to do with something else ????

please help me to c wot my users see ???