I agree with the two above posts. The reason that secondary fermenters were used in the first place was so that you could get the beer off of the yeast. This is a problem in tall vessels because of the hydrostatic pressure on the yeast that sit at the bottom of the vessel. In homebrewing, buckets and carboys are wide and short compared to the larger commercial brewing fermentation vessels. The pressure on yeast in a bucket or carboy is not high enough to cause yeast lysis (rupture of cell membrane and leaking of yeast guts).
It is also known that the longer your beer sits on the live yeast the more "conditioned" your beer will be. Once the yeast break down all of the easily fermentable sugars they then start to break down undesirable by-products of fermentation. This is advantageous to the brewer because it cuts down on off-flavors.
So the answer to your question is: One month is not a long time to keep beer in a primary. Your beer will taste better the longer it is in the primary (as long as the temp doesn't rise higher than ~78 F.) Secondary fermenters are of no use to home-brewers except for dry-hopping, fruit beers, and lagering.
Hope this is enlightening. Much appreciation to Palmer and Zainasheff for most of my beer knowledge.
Billy
