problem in adding more then 3 internal networks to VM

we are trying to execute default workflow

Liberary-->vCloudDirector-->vApp->VM->NIC->Add a NIC

in a loop for adding 8 interanl networks but it gives the following exception after crating 3 internal networks

"All possible network card addresses are in use (Dynamic Script Module name : calculateNextNetworkCardAddress#12)"

we have vm hardware version of 8 and we are asume it should added 10 networks.

will appreciate your help in this regards