PSObject bug with specific parameter - powershell

Question

I have a powershell script that does some simple auditing of group membership on remote servers. The output is as expected except in the case of one group.
There are two parameters two this script, an OU to check in AD and a Group name to check. The OU parameter returns a list of server names, the Group name is the group to return members on. This all works fine except in one case, Backup Operators.
param([parameter(mandatory=$true)][string]$region,[string]$group)
### Debug flag for viewing output when running the script.
$DEBUG = 1
$self = $myinvocation.mycommand.name
function cmdopts {
if ($DEBUG) {
write-host "$self running with options"
write-host "Region: $region"
write-host "Group: $group"
}
}
### Function to handle custom messages to the user.
function usageRegion {
# Removed for brevity
}
function usageGroups {
# Removed for brevity
}
### Cleanup from previous run of the script.
function cleanup {
# Removed for brevity
}
#### Function to load powershell modules at runtime
function loadmod {
param([string]$name)
if ( -not(get-module -name $name)) {
if (get-module -listavailable| where-object { $_.name -eq $name}) {
import-module -name $name
$true
} else {
$false
}
} else {
$true
}
}
### Main()
cmdopts
#### Validate commandline options
if ( "cnr","nwr","swr","ner","ser","emr","lar","apr" -notcontains $region ) {
usageRegion
exit
}
if ( "Administrators","Backup Operators","Event Log Readers","Hyper-V Administrators","Power Users",
"Print Operators","Remote Desktop Users" -notcontains $group) {
usageGroups
exit
} else {
### We are creating three files for each run, previous runs need to be cleaned up before we start.
cleanup
### The ActiveDirectory module is a dependency for this script, we use it to get a list of machine names from AD for the OU.
if ( loadmod -name "activedirectory" ) {
write-host "Loading ActiveDirectory powershell module..." -foregroundcolor green
} else {
write-host "Sorry, you do not have the ActiveDirectory powershell module installed." -foregroundcolor yellow
write-host "The script cannot contnue." -foregroundcolor yellow
exit
}
### Get the list of servers from AD for the OU specified by the user.
get-adcomputer -f * -searchbase "ou=$region,ou=servers,dc=domain,dc=com" | select name | out-file "c:\scripts\ps\$region.srvtmp.txt" -append
### We need to fix some format issues with the file before continuing
# Removed for brevity, cleans up the file output from get-adcomputer and sets variable $srvlist
$srvlist = gc "c:\scripts\ps\$region.srvlist.txt"
# Store for the return
$store = #()
# Fix the group string for the filename
$filestring = $group
$filestring = $filestring.replace(' ', '')
$filestring = $filestring.tolower()
foreach ( $srv in $srvlist ) {
if ( $srv -eq "bustedserver" ) {
# This box hangs and does not tear down WMI when it can't complete, timeout does not work
write-host "skipping $srv"
} else {
$response = test-connection $srv -count 1 -quiet
### This does not work super well, might have to try a custom function
if ($response -eq $false ) {
write-host "$srv was offline during test" -foregroundcolor darkmagenta
} else {
write-host "Checking $group on " -nonewline; write-host $srv -foregroundcolor cyan
$groupinfo = new-object PSObject
$members = gwmi -computer $srv -query "SELECT * FROM Win32_GroupUser WHERE GroupComponent=`"Win32_Group.Domain='$srv',Name='$group'`""
$members = $members | sort-object -unique
$count = 0
if ($members -ne $null) {
add-member -inputobject $groupinfo -membertype noteproperty -name "Server" -value $srv
add-member -inputobject $groupinfo -membertype noteproperty -name "Group" -value $group
foreach ($member in $members) {
$count += 1
$data = $member.partcomponent -split "\,"
$domain = ($data[0] -split "=")[1]
$name = ($data[1] -split "=")[1]
$line = ("$domain\$name").replace("""","")
add-member -inputobject $groupinfo -membertype noteproperty -name "Member $count" -value $line
}
}
if ($DEBUG) {
write-host $groupinfo
}
$store += $groupinfo
}
}
}
}
#$store | export-csv -path "$HOME\desktop\$region-$filestring-audit.csv" -notype
$store
If I run this script against a group like Administrators, or Remote Desktop Users the output looks like the following.
Server: SERVER1
Group: Remote Desktop Users
Member1: GroupName1
Member2: GroupName2
Member3: GroupName3
If I run this script against the group Backup Operators, I only get the first group even if there are many. In the debug write-host statement, it will show all of the groups. When printing the store, it only shows the first one. Even if there are two or more, it will alsways print...
Server: SERVER1
Group: Backup Operators
Member1: GroupName1
Any ideas on why this is broken specifically for 'Backup Operators' and not others would be appreciated.