Problem accessing memory on ISA slot

I have a non-PnP ISA card which is one IO port range and one Memory
When I install the driver on XP, the OS does not show any conflicts for
the resources. But when I look at the registry
HKLM\SYSTEM\CurrentControlSet\Root\MyDevClass\0000, the LogConf ->
BasicConfigVector -> Click on Memory Entry->Display, the pop-up window
show that Access : Invalid.

This is the first time I ever had to write a driver for ISA on XP. Any
pointers to the problem would be of great help.