Ok, I use box mixes (Pillsbury w/pudding) but, have never had one that was dry. I like to freeze may cakes also, which to makes them more moist.
But, the cake I done for my stepdaughters bday, was extremely dry. It was only in the freezer for 3days. I like to bake at least a week out, but prefer 2weeks.
Let me ask this: Where I live, I have well water. So, I have always used bottled water for my cakes. I have noticed a difference recently in their taste. The only thing different is the type of bottled water.
I like just plain drinking water myself, but DH got spring water instead.
Could the water have made the difference or could I have just gotten staled boxes of cake mix? I always check the dates and they were not expired by no means...
Thanks and now I off to finish my Christmas shopping...

I'm not sure about this one. I doubt it was the water though.
Could your oven temperature be off possibly?
Did you simple syrup the cake?

I've never used simple syrup before. As for my oven, I'm not sure, but how would that make a cake dry? just curious. I set my oven temp on 325
What does simple syrup do for the cake? Can you buy this at wal-mart or winn dixie?

If your oven is running hot, it could have overbaked your cake making it dry. You'll need to check it with an oven thermomeer. Simple syrup is something you make.

Once I read Pillsbury, I said BINGO! By any chance, was the cake chocolate?
I used a Pillsbury dark chocolate before, and the next day that cake was so dry!...and it was covered in fondant AND closed in the box! I, too, bake at 325, and know I didn't overbake it.
If you ask me, I say it was the mix.

It was a yellow cake. I have always used this cake mix and have not had any problems with it.
Is the recipe for simple syrup posted on this site?

2 things I highly recommend.
1) an oven therm. -- ovens always fluctuate in heat. They never hold at a steady temp while on. If your ovens temp. is way off it could be set at 325 and be baking at a much higher temp.
2)use a simple syrup. It can be 2 parts sugar to 1 part water and boil/simmer till sugar is dissolved. Some people use equal parts water and sugar instead. It can be also coffee syrup, liquor, vanilla..etc.

As for the simple syrup, how do you use it? Do you put a light coat on the cake? Also, does it make it more sweet? buttercream is to sweet as it is.

I will have to ck my oven temp, it is quite OLD....

A simple syrup spray will only help if the cake has not dried out grealy in the oven. It cannot add enough moisture if it has already been baked out.
It sounds like your oven might be running hot.
Do you bake only by time or use your nose? If you can smell it it should be done....test w/a toothpick & if it comes out mostly clean remove it from the oven. If the cake has pulled away from the sides of the pan most likely it is overbaked.