Cannot export certain attributes that ARE populated

Hi,

Can anyone explain why when using QAD cmdlets I cannot eport certain attributes? eg, if I run the following

Get-QADUser * -searchroot 'ou=users,dc=domain,dc=com' | select -property name, displayname

The displayname attribute is exported but if I run

Get-QADUser * -searchroot 'ou=users,dc=domain,dc=com' | select -property name,extensionAttribute1 no data is exported even though the attribute is populated

Many thanks