Acrobat 9 Check Box Field gives square instead of check mark 1

[IMacQuarker]

Using Adobe Acrobat 9 Pro with Mac OS 10.4.11.
Why would my check box field stop giving me a check mark and give me a black square instead?
Just started having this problem and wonder what font Acrobat uses to give the check mark.
Help fixing this problem would be greatly appreciated.

IMacQuarker

 

[MarkWalsh]

Under the "Options" tab for the checkbox properties, check to make sure that the "Check Box Type" is set to "Check" instead of "Square

 

[IMacQuarker]

MarkWalsh, thanks
You're right I had selected square for some reason, and thought that was the shape of the enclosing box.
But I've done worse.

IMacQuarker