I am going to quote my previous post:
Maybe you can post an anonymous copy of your ics file?
Without more information this is going to be difficult to resolve.
Edit: Somehow the dates in the parsing are being ported back to a date before 1970, probably because a year is not passed or interpreted correctly. Additionally it might be useful to know when you last updated (when it was still working) and at what point in time it stopped working, this would limit the changes we have to look at a little bit.