It could be several issue. Old malt extract from a kit that has been sitting for a long time (the Octoberfest kits are limited release kits), your water, high fermentation temps, steeping grains at too high of a temp, crap yeast (these guys love muntons which is awful), sanitation, or many others.
My first though is the yeast. Second is the fermentation temp.
The first thing you should do if you ever buy a True Brew kit again is toss the muntons yeast in the trash or add it during the last 10 minutes of your boil to use as a yeast nutrient, then replace it with a packet of a decent dry yeast such as US-05 or Nottingham.
While an Octoberfest can be fermented with ale yeast with decent results the style is typically fermented with Lager yeast. Check out biermunchers Ocoberfast for a tasty version fermented with ale yeast. Look through the post. Someone did convert it to an extract recipe as well. http://www.homebrewtalk.com/f63/biermunchers-oktoberfast-ale-ag-39021/index2.html