I don't really have a cake 'disaster', but I do need some advice. I have pretty much mastered the fondant and now feel comfortable covering my cakes and getting a smooth finish. My problem lies with the 2 layers of cake. No matter how I fill my cake, once the cake is covered and stacked, I end up with a bulge where the layers meet. I've tried more buttercream between the layers, less buttercream between, I 've tried not spreading the buttercream all the way to the edge but nothing seems to work.

What kind of BC are you using?  Do you pipe a dam before you fill it?  Do you let your cakes settle?

We can help, but we just need more details.  :)

APretty cake though. Did you cover the sides with bc before the fondant or just fill the middle?

Ahttp://cakecentral.com/t/633571/my-newest-trick

This thread talks about how to prevent the cake from bluging

ABy the way your cake is so cute!!

I used to have this problem. Once you fill in the layers, before doing a crumb coat, I always press down on the cake for all the excess of cake to come out and I wipe it off with my spatula. Since fondant is quite heavy it presses on the cake and makes the buttercream come out which causes the bulging. Hope this helps.

I've recently started doing dams and now wouldn't do a cake without them. Before hand it was sort of give or take as to whether or not the cake would end up with a bulge - with a dam no such problems. You should definitely try it. Also, (as Annie says), you need to let your cake 'rest' before covering with fondant - I do this over night if possible with a glass bowl resting on top to let out any residue air. I read on here once about someone - I think it was LeahS - who puts a tile on top of hers (that's where I got the idea from except I didn't have a tile so use a glass bowl). 

A little less filling may also help.

I make my own buttercream, usually with all shortening and no butter. Not sure what you mean by piping a dam, so I guess the answer would be no. I do frost the sides and top also, and I do press down trying to settle the cake after filling, before I roll on the fondant. I am assuming that it is due in part by the weight of the top layer as it doesn't seem to be as bad on the top layer of the cake. I am wondering if my fondant is rolled too thin. 

Is this done before do the crumb coat? What is the purpose?

Thank you for all the compliments.

It is done between the cakes. Have you ever watched CakeBoss? Buddy does it all the time, alternately you can google it for images if you are a visual person. Basically, you cut your cake in half or bake it in 2 halves. Make sure the halves are even. Pipe a dam with an open tip or just snip the end off of the piping bag, fill with a stiff bc or ganache (which I use) and then fill the middle with a softer cream and you can even add fruit (but then it needs to go in the fridge something I avoid) or chocolate chips or nuts or whatever and then you cover it with the top layer of the cake and then cover as usual with bc or ganache - then you let it settle.

AThe dam is a very thick buttercream that is piped about 1/4 of an inch from the cake's edge on the bottom layer of cake. You then put the filling inside that dam and then the next layer of cake, repeating if you do a three layer cake. It is done prior to the crumb coat. You can use your normal buttercream and add more powdered sugar to thicken it.

Here's a blog that shows you in pictures what you should do.

http://www.thatreallyfrostsme.com/2010/06/dam-filling-full-speed-ahead.html

This is a great video to watch.  She talks about bulging and shows how to dam a cake.  Make sure your dam icing is a thicker consistency. That's def important.