That message comes from apt, not dpkg. It means that the downloaded package did not match the package index. That can be due to interrupted or corrupted downloads and out-of-sync metadata, which can in turn be due to a variety of causes (e.g., see bug#582352). Luckily regardless of the cause the workaround is simple: 1. run "apt-get update" to update the package index files 2. try to install playonlinux again. Sorry for the trouble and hope that helps, Jonathan