JPGs won't 'open with' Irfanview

Hello all,

When I select a .jpg file and right click to "Open With" Irfanview,
the file instead opens with Microsoft Photo Editor. All my other
"Open With" choices work properly. For example, I can use "Open
With" ACDsee, Paint, Digital Image Pro, PhotoImpact with no problems.

The file association is set properly, and if I double-click (left)
on a .jpg, it will open as expected in Irfanview. It appears that
only the right-click "Open With" option doesn't work.

The jpg files had been erroneously opening with Windows Picture and
Fax Viewer, but I unregistered shimgvw.dll, and it stopped doing
that. However, now it uses the Microsoft Photo Editor program
rather than Irfanview.

What other things can I do it get jpg files to properly open on a
right-click?

Thanks for your ideas and help.
Rose