Ok... i'm getting a bit closer to at least figuring out what the interruption in dates is!
It has to do with my system, and how dates are retrieved -- back to your original thought on an 'incorrect date' gives that 1969 result.
That said... after I saved the events from my previous post, then went back to look at them... this is what I saw:
See? I think it's taking the dates entered (example in myd) 01/01/2010 as Jan 01, 2010. however I think it's taking 01/02/2010 as Feb 01, 2010, instead of Jan 2, 2010 ... Am I right? That makes sense, as dates entered from the 13th and beyond wind up with the 1969 year!
So, the underlying question now is "WTF" does it do that?
Sure hope this helps.