Your screen does not show the OP picture ??
ONCE Again !!
If you will read the OP's problem-- "The screw won't tighten" ! So if it was 1/4" to long it would bottom out. Not go all the way in as depicted in the first picture and spin..A lot of these debates/debacles could be avoided if everyone would at least read all the posts. especially if your going to question someone.Don't jump at your first assumption. You might miss something !!
I suspect the OP'er is like a lot of us. I would have done the same thing-- I'm not going to take the time to look up a 50 cent screw on the computer and wait until next week to get it. And then take the chance you could still get the wrong part.. If I remotely think it can be fixed with a trip to my local store.. I'm going to fix it NOW.