Reference map coordinate out of range?

[N Zhou]

Hi,

I'm using the demo mapserver to show my own layers. When I query a layer, I
got error message of:
        loadForm(): Web application error. Reference map coordinate out of
range.

I checked the URL query which seems to be right. The coordinates are also
within the map extent.
Can anybody tell me why I have this problem?

Thank you very much!

N. Zhou