Scott, I have to agree with you there. I have had some instances of freezer-burn on my stock cubes. However, I've found it takes longer than a couple months. Usually, it takes me about 6 months to start developing freezer-burn.
I store my stock cubes in a gallon ziplock. I can't squeeze all the air out, although I try my best. However, this time of year, I go through stock really fast, as I make a lot of soups. In the summer, I don't go through as much stock.
I like your idea of filling baggies with a little bit of liquid and sqeezing out the air, then freezing.
I do the ice cube thing with stock because as strong as I concentrate my stock, one stock cube in a measuring cup, and enough water to fill to one cup, makes a good basic stock. I tend to use that ratio whenever I'm using stock. Of course, sometimes I like a really rich stock, so I use more stock cubes.