The existence of /usr/sbin/squeezeboxserver_safe is found on my machine, and "sudo /etc/init.d/logitechmediaserver" starts the media server here, checked it with the 127.0.0.1:9000 on a browser which brought the email registration wizard. I did just now add a check in the repo's startup script before adding the squeezeboxserver user, but that would not have an impact on what we are testing here.
When there are tar or mksquashfs errors when packing or unpacking archives due to lack of space or any other reason, there are many ways possible that it can affect the outcome. For whatever reason there are out of space or unpacking/mksquashfs errors, I suspect that is the source of the problem. I just tested this import on my box, and before importing df returned a 1730MB available on my disk, and the size option of imoportsce returned a 1729.53MB available. The size data in the Debian repo's Packages file is where the estimated size comes from, so should be fairly accurate. Here, the estimated size of the resulting SCE is overestimated by importsce by 24MB, 109MB is what the sce is when containing no deps, 133MB is what is estimated. And I would rather have a slight overestimate than the opposite. I used the "worst case scenario" in space calculation of the final sce to avoid errors.
Thanks for you interest and testing, let me know how it goes. Yeah, I have always liked Debian too, I first used it when Sarge was going stable.