Pool member control issue when non-default partition is used

Yep, screen in first post was from lab where I run version 10.2.x, so it was related to partition. But then I continued in version 11.x.x so it was really related to version.

Anyway, I corrected code, so it is 11.xx friendly and I am back in partition problem (the same error code 16908336 (0x01020030) as in the first post). Here is the full code:

(Get-F5.iControl).ManagementPartition.set_active_partition( ( ,"MyPartition"))
$pool_name = "lipe_pool"
$member = "10.147.140.61:80"

$vals = $member.Split( (, ':'));
$member_addr = $vals[0];
$member_port = $vals[1];

$MemberDef = New-Object -TypeName iControl.CommonAddressPort;
$MemberDef.address = $member_addr;
$MemberDef.port = $member_port;
$MemberDefAofA = New-Object -TypeName "iControl.CommonAddressPort[][]" 1,1
$MemberDefAofA[0][0] = $MemberDef;

$MemberStatisticsA = (Get-F5.iControl).LocalLBPool.get_member_statistics( (, $pool_name), $MemberDefAofA);

And here is the result when I try the last command:

I am really trying to find solution for that, but still not successful. Is it really something bad in F5, or do I miss something still? Thanks a lot, Zdenek