[AccessD] A table that can't be duplicated

The main table in a database won't be copied. Access says another user is
busy with the table. But this is not so.

I can't copy the table and rename the table, I can't import it into another
database, I can't use a MakeTable query to do it that way. 

I can copy the whole database, but that same table in the copied database
refuses to be copied - or to be renamed.

I can steal it with Excel - but then I lose all the lookups and the like.

Anyone had this problem before please, anyone found an answer, please? 
Cheers paul