The current practice is to mark bugs "fix released" in Launchpad when committing to SVN. The rationale for this (given by bulia in another thread) is that this way the "open bugs" count is more useful for the developers.
I think this is an abuse of Launchpad bug tracking. IMO the rationale isn't sufficient. It creates confusion for users which re-report bugs that have been fixed in SVN, because "fix released" bugs do not show up in search results. There must be a better way of tracking how many bugs have been fixed. Currently I know about advanced search (just search for all bugs with statuses New, Triaged, Confirmed, Incomplete, In Progress) and milestones which can isolate the most important bugs.
Another option is to talk to the Launchpad team to include an "Unfixed" count on the bugs page which would exclude "fix committed" bugs. This will be better than abusing the system and confusing the users in the name of seeing some number.
Regards, Krzysztof Kosiński