Replaced the cartridge in my 6 year old Delta shower faucet.  Water was hard and a lot of buildup was the cause, I think???  Anyway, put in the new cartridge and it leaks worse than before.  I did NOT grease the o-rings as was suggested to me (I simply forgot). Will that make much difference? What grease? I was actually going to use vaseline.  Anything else that I might want to look for when I pull this cartridge back out?

ETA: the weird thing: when I put it together I had no leak for an entire day.  Started leaking after wife and I took first showers with the new cartridge the next day? Not sure if that points to something or not???