PowerShell/ADSI Permission Issue with AD related tasks

I'm working on a PS script that will give users a GUI & a few buttons to click to do some basic tasks such as unlocking an account, enabling/disabling, changing passwords and killing processes / logging user off. The parts that do NOT work are : enable/disable users and change passwords.

First of all, everything works as a domain admin but I can not make the user a domain admin, so please do not suggest that 🙂

Here's the change password part:

    $name = "osman"
    $Searcher = [ADSISearcher]"(sAMAccountName=$Name)"
    $Results = $Searcher.FindOne()
    $password = "pezevenk@321"

    [string]$adspath = $Results.Properties.adspath
    $enable = [ADSI]$adspath
    $enable.psbase.invoke("SetPassword", $password)
    $enable.psbase.CommitChanges()

The Error is pretty generic:

Exception calling "Invoke" with "2" argument(s): "Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))"
At line:14 char:13
+             $enable.psbase.invoke("SetPassword", $password)

Now, obviously, I've tried to give proper permissions to the user before even I attempted this: The user I'm running this with has the "reset password" and "change password" rights delegated on the "Users" folder in AD which includes all the users.

Is there any way to see exactly what permission I'm missing? Can you guys think of anything else that is required?

Edit: These are the permissions for the OU:

"CN=Users,DC=domainname,DC=root,DC=com","All","User","ReadProperty, GenericExecute","Descendents","00000000-0000-0000-0000-000000000000","bf967aba-0de6-11d0-a285-00aa003049e2","InheritedObjectAceTypePresent","Allow","domainname\osman","False","ContainerInherit","InheritOnly"
"CN=Users,DC=domainname,DC=root,DC=com","Pwd-Last-Set","User","ReadProperty, WriteProperty","Descendents","bf967a0a-0de6-11d0-a285-00aa003049e2","bf967aba-0de6-11d0-a285-00aa003049e2","ObjectAceTypePresent, InheritedObjectAceTypePresent","Allow","domainname\osman","False","ContainerInherit","InheritOnly"
"CN=Users,DC=domainname,DC=root,DC=com","Lockout-Time","User","WriteProperty","Descendents","28630ebf-41d5-11d1-a9c1-0000f80367c1","bf967aba-0de6-11d0-a285-00aa003049e2","ObjectAceTypePresent, InheritedObjectAceTypePresent","Allow","domainname\osman","False","ContainerInherit","InheritOnly"
"CN=Users,DC=domainname,DC=root,DC=com","User-Account-Control","User","WriteProperty","Descendents","bf967a68-0de6-11d0-a285-00aa003049e2","bf967aba-0de6-11d0-a285-00aa003049e2","ObjectAceTypePresent, InheritedObjectAceTypePresent","Allow","domainname\osman","False","ContainerInherit","InheritOnly"
"CN=Users,DC=domainname,DC=root,DC=com","User-Force-Change-Password","User","ExtendedRight","Descendents","00299570-246d-11d0-a768-00aa006e0529","bf967aba-0de6-11d0-a285-00aa003049e2","ObjectAceTypePresent, InheritedObjectAceTypePresent","Allow","domainname\osman","False","ContainerInherit","InheritOnly"
"CN=Users,DC=domainname,DC=root,DC=com","User-Change-Password","User","ExtendedRight","Descendents","ab721a53-1e2f-11d0-9819-00aa0040529b","bf967aba-0de6-11d0-a285-00aa003049e2","ObjectAceTypePresent, InheritedObjectAceTypePresent","Allow","domainname\osman","False","ContainerInherit","InheritOnly"
"CN=Users,DC=domainname,DC=root,DC=com","User-Change-Password","User","ExtendedRight","Descendents","ab721a53-1e2f-11d0-9819-00aa0040529b","bf967aba-0de6-11d0-a285-00aa003049e2","ObjectAceTypePresent, InheritedObjectAceTypePresent","Allow","domainname\osman","True","ContainerInherit","InheritOnly"
"CN=Users,DC=domainname,DC=root,DC=com","User-Force-Change-Password","User","ExtendedRight","Descendents","00299570-246d-11d0-a768-00aa006e0529","bf967aba-0de6-11d0-a285-00aa003049e2","ObjectAceTypePresent, InheritedObjectAceTypePresent","Allow","domainname\osman","True","ContainerInherit","InheritOnly"