The OSCAR messenger generates and stores an XML 'address book' for messaging groups. However these XML strings don't get updated when the provider records are updated.
Considering that the provider names in the groups are not editable in the OSCAR frontend, and that parsing the XML incurs unnecessary overhead, as a bugfix I would propose replacing the XML address book with two database tables: One that has a list of groups (to make names and other properties editable) and one that links providers to groups. This would make OSCAR always pull the updated names from the provider records.