What can't users access certain files off our intranet?

Hello,
I have our corporate intranet site running using IIS on Server2003.  I handle the back end but do not get into the graphics.  Everything was working perfect until I edited two .pff files (these are Formatta Form Filler files).  I opended the original, saved it to .old.  Then edited the original and saved it as the original file name.  The folder that contains these files is on the web server, so IIS points to that folder.  Now when my users (all running XP) try to access any PFF files from the intranet (using IE7 or IE8), they get the followinger error:

Access to c:\doc and settings\username\local settings\temporarey internet files\content.ie5\various numbers\Filename.pff was denied.

All other files in the folders with the PFF's work find.  If I map to the web server folder from one of the clients, I can open the PFF files with no issues.

Again, all PFF files could be accessed until I did the two edits.
Any input appreciated.
Thank you,
BG