New Post: Category sub menu sequence is wrong

Hi, I have a problem with the category module:

I defined in BO categories:
100 Software

110 Databases

200 Copter

210 XXX
220 YYY

when I click on "Software" category on the page I get displayed:
Software
Copter

Databases

I do not understand, why appears "Databases" under "Copter" and not under "Software"???

many thanks