cvs corrupts file while tagging

[rush]

   Hi,

   I'm facing to a strange problem: cvs corrupts rcs file while I'm trying
   to tag it.

   The file itself is about 50Mb (and it's binary) and rcs file is about
   2.1G.

   Every time I launch

   cvs rtag -B -a -F -r 1.526 -b "my_tag" project/file.bin

   rcs file turns from 2.1G into 110K file with completely lost history
   and file itself.

   All other operations (commit, update, etc) works fine.

   е║

   This is the biggest file in repository and the only file with such
   behaviour on tags. Others are working fine.

   I'm using Concurrent Versions System (CVS) 1.12.6 (client/server)

   Is there any way to fix that thing?

   е║

   --
   wbr,
   rush.