Little Big Planet: Can't Bolt! Why?!

So, I'm doing the tutorial for create mode on LBP right? I get to bolting. Apparently you select a bolt, move the cursor to an object, and press X to put a bolt on it. Then, you take the bolted object and drag it over to another object, and then press X to bolt it to said object. Well, I select the normal bolt, and everytime I put the cursor over the object I want to put the bolt in and press X, it just makes that funny, ''sorry loser, you can't do that,'' sound. What the heck am I doing wrong?