I wrote:

I've searched the changelog for binutils 2.14 and did not find any mention of such a patch.

I spoke too soon. The FSF binutils does not mention a fix for this problem; however, the 20030807 Mingw binutils snapshot does appear to contain a patch. See: ftp://ftp2.sourceforge.net/pub/sourceforge/mingw/binutils-2.14.90-20030807-1-notes.txt which says, in part: The 2.14.90-20030807-1 snapshot incorporates modifications to official binutils CVS since last update. It also fixes a bug (again) with w9x fseek, where file contents are not zero'd out if you seek past the end and then write. This patch has not been in recent binutils releases. So perhaps the OP can use that binutils snapshot (available at the same FTP location, or via http://www.mingw.org/ ) to work around the problem on Win9x. -- Dave