Even if I already new that often (or continuous) integration is the key to achieve a zen developper attitude.
I recently descovered that merging branchs in cvs has to be run often to reduce any conflict nigthmare in cvs.
Someone (or better everyone in the team) should make an intermediate-merge during the life time of the branch.
If you don't do that, the branch'team will work on "out of date" sources with bugs that had been corrected on the HEAD chunk long time ago.
The longer you wait for an inter-merge the more you get conflicts and that's not what you want!