This "feature" of Windows has been pointed out many times before. You can have a bit of fun re-naming a reasonably sized .jpeg to .doc and see the poor sod open it up in Word, tied my mates machine up for ages - oh how we laughed :-D
-Cecelia: Didnt know about ACDsee, but DirOpus8 for windows ALWAYS opens it correctly, no matter what suffix is used (or indeed if none is used at all). Just goes to show what quality of programmers the Amiga has always had - past and present.
-jd