Infotype Screen Modification

Hi All....

I've created a custom infotype with say 3 fields out of which one needs to be displayed as a check box. For this I've deleted that field from 2000 and recreated the it as a check box. Now, when I try to process the infotype in PA30, the modified field is disabled (greyed out)...I cannot moify the screen attributes also as it'll affect other functions like diaplay of infotype records...

Can anyone please suggest the reason for this????

Thanks and regards

PI