The Ongoing Saga of the Mac that Wouldn't Sleep (properly)

Steps I have taken to correct the issue:
1. Re-set power management
2. Re-set sleep image
3. Deleted power management setting (reinstalled after restart)
4. Deleted widget with known issue
5. Removed programs that I thought could be causing the problem (programs I had borrowed)
6. Swapped out RAM (Upgraded in the process)
7. Changed screen saver setting

I have looked into this quite a bit and tried anything I can to correct the issue. Changing the screen saver setting actually seems to have worked, but as with the other fixes, they all seem to work and then it goes back to failing. Since I changed the screen saver setting 2 days ago (to not come on ever), I haven't had a recurrence of the issue. I think my next step might be to re-install OSX from scratch. I would prefer to not have to do this, but I am running out of ideas.