Please, don't be sorry! I'm more than happy to try and help in any way we can :-)
I haven't come across this before... But then, I've never come across your particular issue before either.
I think if I were in your shoes I would begin considering reformatting my mac and re-installing everything from scratch(!)
But before doing this, I'd create a complete clone of my mac on to an external HD using an app like Carbon Copy Cloner.
I'd also backup any important files etc.
However, before you even consider taking such a drastic step, check again that you have all available updates (use software Update from the Apple Menu)
install them, repair permissions and restart your mac.
Also if you like (before formatting your mac) you can send me one of the songs and I'll try it out here on Logic 8 and see if your logic project might be corrupt. (I suspect it's not, but this will at least inform us of that).