Rita,
The newid() function resides in the DBC as a stored procedure. It uses id.dbf to locate the name of the table of either the currently selected alias or the name supplied as a parameter in the newid call (newid('MYTABLE')).
Make sure your Database Container's stored procedures contains this function.
Gil Munk
"If a nation expects to be ignorant and free, it expects what never was and never will be." - Thomas Jefferson