Cannot Open some JPG Files

I have a user that has jpg's emailed to her, but she cannot open them. They
actually come in with what looks like a Quiktime logo. When you try to open
the picture it says "couldn't display xxxx.jpg because a suitable graphics
importer could not be found". It seems to be trying to open the pictures
with Quiktime viewer, even though the jpg file association says to open the
files in Microsoft Picture Manager. I have gone into Quiktime and turned off
the option to open jpeg's with the Quiktime viewer, but that didnt seem to
work. Whats odd is that if this user forwards those pictures to me, and I
save to my hard drive, open them, and then send them back to her, they open
fine. Does anyone have any idea what is going on here?
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TO FIX IT
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What I did determine is that a security update for Outlook (KB945432) was
the culprit. I uninstalled that hotfix and rebooted the computer, set up the
correct file associations again, and the jpg's opened.