Add object

Hi,

I've got an IP subnet object whith the caracteristics 
        Sel name : 11.109.19
        IP addr  : 11.109.19.0
        Mask     : 255.255.255.0

When I enter into its submap and try to add an object, say 'DeviceA'
with address 11.109.19.253, I get the following info while setting
object IP Map characteristics (add object box) :
        Sel name : DeviceA
        IP addr  : 11.109.19.0          <-- ???
        Mask     : 255.255.255.252      <-- ???
If I change address to 11.109.19.253 and Mask to 255.255.255.0 I get the
message saying the subnet mask is not the one corresponding with the
submap!!!????

Could anyone explain whats going wrong? Thanks
        
Alain

-- 
Alain Menezes                                   Email: a.menezes AT cger DOT be
ASLK-CGER Services GIE                          Tel.:  +32 2 228.55.74
Rue Fossé-aux-Loups, 48                               Fax.:  +32 2 228.83.69
1000  Brussels