sed produces strange files

Hello all,

I  have  a  problem  when  using  sed  with  the  -i
(--in-place) option.  Upon processing a file, a  new
file named like sedYNFdj6 appears in the working di-
rectory and contains an exact copy of the  resulting
file.  I was using this command line:

              sed -i -e 1,5d test.txt

with sed 4.2.1.  I don't think these files should be
created.

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