If you ever come across an issue where you cannot remove the queued reports (failed) from queued status, follow the approach suggested here.
In addition to this, enjoy the two tips below
1. If you wonder how you can connect to MR when away from a domain network, the best solution would be to connect to your domain through a vpn connection. Once it is connected through a vpn to your domain, it works the same way as you are within domain.
2. When you run the reports in MR Report designer and if you see the reports are just queued and not processing further to view the reports, then the culprit might be the Management Reporter Process service. Go to Start | Run | Services.msc, locate Management reporter process service and start the service.