[Rd] package NULL not found

[Gabor Grothendieck]

In performing Rcmd check I am getting this output regarding using
Argument '' and a NULL package not found and it stops with an error:

* using log directory 'C:/Rpkgs/sqldf.Rcheck'
* using ARGUMENT '
' __ignored__  R version 2.5.1 (2007-06-27)
* checking for file 'sqldf/DESCRIPTION' ... OK
* this is package 'sqldf' version '0.1-0'
* checking package dependencies ... ERROR
During startup - Warning messages:
1: there is no package called 'NULL
' in: library(package, lib.loc = lib.loc, character.only = TRUE,
logical = TRUE,
2: package NULL
 in options("defaultPackages") was not found
See the information on DESCRIPTION files in the chapter 'Creating R
packages' of the 'Writing R Extensions' manual.

My DESCRIPTION file looks like this:

Package: sqldf
Version: 0.1-0
Date: 2007-07-19
Title: SQL on data frames.
Author: G. Grothendieck
Maintainer: G. Grothendieck <ggrothendieck at gmail.com>
Description:  Thin layer over RSQLite and RMySQL facilitating use of
SQL selects on data frames.
Depends: R (>= 2.5.1), RSQLite (>= 0.5-5), gsubfn
License: GPL (Version 3 or later)
URL: http://code.google.com/p/sqldf/

and the entire package is at (click on Source tab):

   http://code.google.com/p/sqldf/

I am using
> R.version.string # Windows XP
[1] "R version 2.5.1 (2007-06-27)"

Does anyone know what this means and how to fix it?

The package itself seems to work.  Its just getting it past Rcmd check
that is the problem.

Thanks.