Andy, I'm unsure of the strategy used for the oil life monitor on the 04s...
but, AFAIK, it is simply a mile/time based display with no other
computations considered....

The only thing that I can think of is that the lube monkey may have
inadvertently "personalized" your oil change preference. Page 76 of your
owners guide explains how to both reset the message and personalize this
setting....

If you don't have the owner guide, you can download on from
www.motorcraft.com ... select techical resources near the top and then
select owner guides on the left of the window that pops up.

HTH.