Ange-ftp or tidy blanking some *.htm transfers

[Steve]

After ange-ftp login to my ftp server, remote directory displays.
C-x C-f retrieves some *.htm files no problem. But others show 
the "retrieving .." message then stop and ask if "auto-insertion"
is wanted (for a blank document). The only message that seems new
is "config file loaded". Is tidy or other .htm -triggered lisp 
program reading code on these pages that causes the program to 
blank the retrieved file? Stylesheets?

Thanks for suggestions