New GW 8.0 functionality in Admin API not working

[johnbaird]

Anyone else attempted to use this? According to the docs, functions such as
get_LastClientType, get_MailboxLastLoginDate and get_MailboxSize should work
on 8.0. However based on a non-random sample of one installation, converting
to the IADUser4 interface fails on 8.0 with 0x80004002 which usually
indicates "not supported" and on 8.0 SP1 the conversion succeeds but each of
the 3 above functions return zero values.

Any suggestions appreciated.
John