[otrs] customer informations not been shown when creating a ticket

hi, i have a strange behaviour on my otrs installation. i use a backend db connection for our customer data. this works pretty good after some tricky configuration issues. now, when i want to create a ticket i can search for the customer and this works well... but, on the right side where the customer informations should be display, there is nothing shown. why? i also find out, that when i try to access the customer user management in the admin section i can search the customers, but when i click on them the parameters that was taken from de backend db are empty... is there any connection between these two issues? thanks for your help. regards, patrick.