specifying stream by uuid for compare and lock commands sometimes fails with "invalid item type; expected stream, received workspace". why?

{

    "workspaces": [

        {

            "components": [

                {

                    "name": "AUTOMATION_FRAMEWORK_PRODUCT_INFO",

                    "uuid": "_u0abcRj_EeKrjsmMOIX_gQ"

               },

                {

                    "name": "AUTOMATION_FRAMEWORK_SHELL",

                    "uuid": "_4-2vwQikEeKrjMmMOIX_gQ"

                },

                {

                    "name": "AUTOMATION_FRAMEWORK",

                    "uuid": "_-j3hwPzCEeGrjMmMOIX_gQ"

                },

                {

                    "name": "XT_AUTOMATION_FRAMEWORK",

                    "uuid": "_b-Y38AipEeKrjMmMOIX_gQ"

                }

            ],

            "flow-target": {

                "name": "automation_framework_xt",

                "type": "STREAM",

                "url": "https:\/\/feiclm.w2k.feico.com\/ccm\/",

                "uuid": "_coEvYBkWEeKrjsmMOIX_gQ"

            },

            "name": "af_xt_Build",

            "url": "https:\/\/feiclm.w2k.feico.com\/ccm\/",

            "uuid": "_vR6iIHLYEeKhPvIBHetUrA"

        }

    ]

}

D:\snaps\workspace\Build-AF_xt-rtc>"C:\Program Files (x86)\IBM\Rational Team Concert Client for Microsoft Visual Studio IDE\3rd Party\scmtools\eclipse\scm.exe" lock release -r "https://feiclm.w2k.feico.com/ccm"  -s "_coEvYBkWEeKrjsmMOIX_gQ" -c "_u0abcRj_EeKrjsmMOIX_gQ" -R "/project.build.xml"

D:\snaps\workspace\Build-AF_xt-rtc>"C:\Program Files (x86)\IBM\Rational Team Concert Client for Microsoft Visual Studio IDE\3rd Party\scmtools\eclipse\scm.exe" lock acquire -r "https://feiclm.w2k.feico.com/ccm"  -s "_coEvYBkWEeKrjsmMOIX_gQ" -c "_u0abcRj_EeKrjsmMOIX_gQ" -R "/project.build.xml"

Problem running 'lock acquire':

Invalid item type for "_coEvYBkWEeKrjsmMOIX_gQ". Expected type "stream" but specified item was of type "workspace". Try 'scm help lock acquire' for more information.

I've seen this happen with both scm lock acquire, scm lock release, and scm compare, and it is driving me nuts :)  It works if I specify the stream by name, but I'd rather use the UUID as names are somewhat mutable.