First: What can I do about this?
---
Could not download all repository indexes

The repository might be no longer available or could not be contacted
because of network problems. If available an older version of the failed
index will be used. Otherwise the repository will be ignored. Check your
network connection and the correct writing of the repository address in the
preferences.

archive.ubuntustudio.org/.../Packag\
es.gz:
404 Not Found [IP: 64.158.56.38 80]
---
The second error comes after the 'update' has completed:
---
E: realtime-lsm: subprocess post-installation script returned error exit
status 1
E: realtime-lsm-module-2.6.22-14-generic: dependency problems - leaving
unconfigured