When artist has begin and end date set to the same year (with no months and days), then it's shown as lasting "0 days". Should be something like "A few months", "Under a year" or "1 year or less" imo.
Some examples (http://musicbrainz.org/search?query=begin:2010+AND+end:2010&type=artist&advanced=1)
Or we display nothing for those, maybe.
Dissolved: 2010 (0 days)
we would have
Founded and Dissolved: 2010
This seems to be resolved with my MBS-5250 work