Option Group Revisited Again, Help

Have a Access 2003 database. Created a new form (not the first form of the
DB) and added an option group frame (unbounded). Added 2 radio button
option buttons (unbounded). Button one is labeled Summary and is the
default value for the option group (value = 1). Button two is labeled
Detail and has the value of 2. I have done this unbounded option group
thing many times in AC2000. The option group frame label is "Choose report
type". The action I am looking for is that one or the other button displays
that it is selected. I then test for the value of the option group to
determine if I display a report with summary data only or summary and
detail. Option group behavior is supposed to be mutually exclusive. Only
one button can be selected. When I run the form the display is as expected.
I have an option frame with two buttons and the default, Summary is
selected. When I try to select Detail button the label is highlighted, but
the Detail radio button doesn't become dark in the center. The Summary radio
button remains selected (dark in the center). I can't get the selection to
move off Summary. Checked all properties and compared them with known
working Ac2000 DB with option groups and buttons. Looked in help, but no
answers. What am I doing wrong? Did something change with option groups
while I wasn't looking and changed to AC2003?
Any help you can provide will be greatly appreciated.