ldapadd "operations error"?

[Martin Smith <mfsmith@erols.com>]

I got a corrupted ldbm database, so I deleted all the files (moved them 
elsewhere, actually), and tried to reinsert the top of the directory 
(c=us) and superuser ID "cn=Manager,c=us) per the QuickStart manual, 
using ldapadd.  

I was successful is searching for "namingcontext", but adding the two 
entries above, I get "operations error".

Any idea what that might mean?  

(I assume that some of the db files would appear in the directory if it 
were working, but none has so far.)

TIA,

Martin