Hi it's my second day in the game. I'm trying for a Munar flyby. I'm using a stack 'o' fuel with a Swivel engine and 2 large SRBs. After having no problems for some time, suddenly I can't attach SRBs to the main rocket. They either miss the separating devices and attach themselves permanently, or they attach with one booster much close to the main rocket than the other, or they will attach with both boosters almost completely INSIDE the main rocket body. I just spent an hour trying to do this without success. The frustration is unbelievable, because it's something I have done in about 2 seconds many times before.
Am I missing something simple here?