Which user account do you want to use to run this program?

Since installing SP3 on a Windows XP home system I frequently get a
dialog box displaying the message "Which user account do you want to
use to run this program?" This pops up when I change the configuration
settings of some of the programs I have installed.

What causes this annoying behavior?

How can I disable it an return to the SP2 behavior?

--
..Bill.