Insulation of components in a breadboard
From the sound of it, your problem is caused by not making sure your breadboard layout it neat enough. This involves triming component leads so they sit flush on the board, and bending them so they match the grid pattern. All to often I see students struggle with debuging their circuit, because half of the time they don't know if the fault is caused by their design or just something wrong in their breadboarding. Because it's a mess, they can't easily check their breadboard circuit and thus lose a lot of time - time they would have saved if they took care in breadboarding the circuit neatly in the first place.

Does your breadboard look something like this:

Then you need to trim the leads and cut cables to lenght. Cable and components are cheap and it's not worth it to waste your time debugging a messy layout for the sake of saving 2 cents worth of resistor.

Compare it to the following:



Note: neither of these are actual circuits, I just threw some stuff onto a breadboard for the sake of demonstration.