Receiving and error while uninstalling RBS on Sharepoint 2010

I am having an issue uninstalling RBS from our content databases.

The steps I've taken are as follows:

1. Migrate the content out and disable via powershell

$cdb = Get-SPContentDatabase <<database name>>
$rbss = $cdb.RemoteBlobStorageSettings
$rbss.SetActiveProviderName("")
$rbss.Migrate()
#wait until completed successfully
$rbss.Disable()

2. Set timeout values and run checkpoint

exec mssqlrbs.rbs_sp_set_config_value 'garbage_collection_time_window', 'time 00:00:00'; 
exec mssqlrbs.rbs_sp_set_config_value 'delete_scan_period', 'time 00:00:00'; 
exec mssqlrbs.rbs_sp_set_config_value 'orphan_scan_period', 'time 00:00:00'; 

CHECKPOINT

3. Run RBS Maintainer

"C:\Program Files\Microsoft SQL Remote Blob Storage 10.50\Maintainer\Microsoft.Data.SqlRemoteBlobs.Maintainer.exe" -connectionstringname RBSMaintainerConnection -operation GarbageCollection ConsistencyCheck ConsistencyCheckForStores -GarbageCollectionPhases rdo -ConsistencyCheckMode r -TimeLimit 120

4. Run uninstall proc on content databases

exec mssqlrbs.rbs_sp_uninstall_rbs 0

At this point I'm getting the following error:

The RBS server side data cannot be removed because there are existing BLOBs registered. You can only remove this data by using the force_uninstall parameter of the mssqlrbs.rbs_sp_uninstall stored pro

I don't know what else to do.  I've migrated all of the data out AFAIK but obviously something is not functioning as other users have experienced.

Can anyone help me?

Jonathan