You need to be careful when you create a table based on the definition of another table (using the Copy from) button. The table File (on the General tab) will be set to the value from the table you have copied. You must change this to another value (or blank it out). If you don't do this, the table will be created using the same file. This can cause all sorts of problems!!
If you have done this, drop the table you have just created using the Drop from Dictionary only option.