Create Fixed Asset from Purchase Order problem


I am facing a problem that when I am creating Quarantine order for an item through Item Arrival, the ‘New fixed asset?’ and ‘Fixed asset group’ fields on ‘Fixed Asset’ tab gets disabled but when I am processing the Arrival journal normally and not creating Quarantine order the said fields remain enable.

Will be very grateful if any one of you could let me know whether this is standard functionality of Microsoft Dynamics AX 2009 or am I doing something wrong?