i also have a p345, i had a problem with ejecting/jamming, not the first time i took it out but the second time and on. I was very concerned and curious so i called ruger... turns out if you put your recoil spring in backwards it can really mess up your ejection situation. Its really hard to notice without close attention, but if you look at your recoil spring one end is wider than the other. You want to make sure when your puting it back togethor after cleaning you put that wide end towards the nose of the pistol (end of the barrel). I made this mistake the second time i cleaned it and after i switched it back i couldn't believe it was such an easy fix, haven't had a jam or ejecting problem since!!!!. Also instead of using thick greases or oils to lube the gun, try rem dri lube! made a huge differance for me as well.
hope this helps.