MBP beeps, wont turn on, acting erratically

I have a MBP running OSX. I installed 8 GB of ram to replace the 4 GB it comes with. Everything was fine, then the computer forced me to shut down. Now, if I have the computer on too long, or if it goes to sleep or turns off, I have to turn it on/off a dozen or so times to get it to load OSX. The first dozen times I get the three beeps. I've read that this means failed ram, but I've tried putting the old ram back in and I get the same issue. Any help?

When you swapped the RAM back did you make sure they were seated all the way? Should click into place.

Yes, I have checked and re-checked the seating as I assumed this was the issue.

How old is the machine? It's possible one of the module female connector contacts may have been damaged in the memory slots. I've seen that happen on several machines. Nothing much you can do if that occurs except swap out the logic board.

tried buying new ram, and it seems to be working fine. Thanks for the help