Philodendreon Mystery

We have a mystery...my mom & i each have a philodendreon plant that have always been beautiful & growing wonderfully year after year....mine came from my mom's (which was my grama's) so it's the same line....all of a sudden the leaves started turning yellow on both our plants & dying off...we thot we were going to lose our plants....day after day we'd take the dying leaves off...finally my mom got so depressed over it she put hers in the basement so she wouldn't have to watch it deteriorate, i kept mine where it was...all i could find on the internet was that yellow leaves were the sign of overwatering...this can't be right b/c neither of us over watered...the main reason i love philo's is b/c they thrive on neglect! my kind of plant! LOL! then lo & behold, about a week & a half ago mine stopped dying off! YAY! mind you, i am left with quite a few bare branches (which i will see if i can trim back later on, after i'm sure it's over with) & my mom's seemd to have stopped also....now i find out a friend of mine who has one, hers is doing the same thing! is there anyone else out there that has a philo that this has been happening to also???? please get back to me if it is & maybe we can get to the bottom of this mystery (which my friend calls "A Curse") ......it could be