This small patch cures a bug which crept into the release of V 1.43b. Just extract the patch from the ZIP file and run it in the same directory as your copy of TSTHOST.EXE
If the date of your V 1.43b TSTHOST.EXE is earlier than 30/10/96 then you probably need to run this patch.
IMPORTANT
If you downloaded your TSTHOST V 1.43b from this site, you do NOT need to run this patch as the EXE file has aready been fixed.