If you update to the latest then it won't work if your using a clone as it has a genuine dreambox check.
It should state in the plugins download list use old webinterface to get around license issues, so if you put on the latest then you won't get around the license issues so it won't work.
I wasn't aware that the latest pli 2.1 had a plugins feed yet ?
Or do you mean pli 2.0 updated ?
Bottom line is the latest won't work on a clone, have you tried the e2openplugin webif that is quite neat and doesn't care about clones